diff --git a/web/app/components/workflow/skill/__tests__/main.spec.tsx b/web/app/components/workflow/skill/__tests__/main.spec.tsx
new file mode 100644
index 00000000000..14e8d50fadf
--- /dev/null
+++ b/web/app/components/workflow/skill/__tests__/main.spec.tsx
@@ -0,0 +1,134 @@
+import type { ReactNode } from 'react'
+import { render, screen } from '@testing-library/react'
+
+import SkillMain from '../main'
+
+const mocks = vi.hoisted(() => ({
+  queryFileId: null as string | null,
+  appId: 'app-1',
+  activeTabId: 'file-tab',
+  openTab: vi.fn(),
+  useSkillAutoSave: vi.fn(),
+}))
+
+vi.mock('nuqs', () => ({
+  parseAsString: 'parseAsString',
+  useQueryState: () => [mocks.queryFileId, vi.fn()],
+}))
+
+vi.mock('@/app/components/app/store', () => ({
+  useStore: (selector: (state: { appDetail: { id: string } | null }) => unknown) => selector({
+    appDetail: mocks.appId ? { id: mocks.appId } : null,
+  }),
+}))
+
+vi.mock('@/app/components/workflow/store', () => ({
+  useStore: (selector: (state: { activeTabId: string }) => unknown) => selector({
+    activeTabId: mocks.activeTabId,
+  }),
+  useWorkflowStore: () => ({
+    getState: () => ({
+      openTab: mocks.openTab,
+    }),
+  }),
+}))
+
+vi.mock('../hooks/use-skill-auto-save', () => ({
+  useSkillAutoSave: () => mocks.useSkillAutoSave(),
+}))
+
+vi.mock('../hooks/use-skill-save-manager', () => ({
+  SkillSaveProvider: ({ appId, children }: { appId: string, children: ReactNode }) => (
+    <div data-testid="skill-save-provider" data-app-id={appId}>
+      {children}
+    </div>
+  ),
+}))
+
+vi.mock('../constants', () => ({
+  isArtifactTab: (tabId: string | null | undefined) => tabId === 'artifact-tab',
+}))
+
+vi.mock('../file-tree/artifacts/artifacts-section', () => ({
+  default: () => <div data-testid="artifacts-section" />,
+}))
+
+vi.mock('../file-tree/tree/file-tree', () => ({
+  default: () => <div data-testid="file-tree" />,
+}))
+
+vi.mock('../skill-body/layout/content-area', () => ({
+  default: ({ children }: { children: ReactNode }) => <div data-testid="content-area">{children}</div>,
+}))
+
+vi.mock('../skill-body/layout/content-body', () => ({
+  default: ({ children }: { children: ReactNode }) => <div data-testid="content-body">{children}</div>,
+}))
+
+vi.mock('../skill-body/layout/sidebar', () => ({
+  default: ({ children }: { children: ReactNode }) => <aside data-testid="sidebar">{children}</aside>,
+}))
+
+vi.mock('../skill-body/layout/skill-page-layout', () => ({
+  default: ({ children }: { children: ReactNode }) => <section data-testid="page-layout">{children}</section>,
+}))
+
+vi.mock('../skill-body/panels/artifact-content-panel', () => ({
+  default: () => <div data-testid="artifact-content-panel" />,
+}))
+
+vi.mock('../skill-body/panels/file-content-panel', () => ({
+  default: () => <div data-testid="file-content-panel" />,
+}))
+
+vi.mock('../skill-body/sidebar-search-add', () => ({
+  default: () => <div data-testid="sidebar-search-add" />,
+}))
+
+vi.mock('../skill-body/tabs/file-tabs', () => ({
+  default: () => <div data-testid="file-tabs" />,
+}))
+
+describe('SkillMain', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.queryFileId = null
+    mocks.appId = 'app-1'
+    mocks.activeTabId = 'file-tab'
+  })
+
+  it('should render the skill layout and autosave manager', () => {
+    render(<SkillMain />)
+
+    expect(screen.getByTestId('skill-save-provider')).toHaveAttribute('data-app-id', 'app-1')
+    expect(screen.getByTestId('sidebar')).toBeInTheDocument()
+    expect(screen.getByTestId('content-area')).toBeInTheDocument()
+    expect(screen.getByTestId('file-content-panel')).toBeInTheDocument()
+    expect(mocks.useSkillAutoSave).toHaveBeenCalledTimes(1)
+  })
+
+  it('should render the artifact content panel when the active tab is an artifact', () => {
+    mocks.activeTabId = 'artifact-tab'
+
+    render(<SkillMain />)
+
+    expect(screen.getByTestId('artifact-content-panel')).toBeInTheDocument()
+    expect(screen.queryByTestId('file-content-panel')).not.toBeInTheDocument()
+  })
+
+  it('should open the query-selected file as a pinned tab', () => {
+    mocks.queryFileId = 'file-42'
+
+    render(<SkillMain />)
+
+    expect(mocks.openTab).toHaveBeenCalledWith('file-42', { pinned: true })
+  })
+
+  it('should fall back to an empty app id when app detail is missing', () => {
+    mocks.appId = ''
+
+    render(<SkillMain />)
+
+    expect(screen.getByTestId('skill-save-provider')).toHaveAttribute('data-app-id', '')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/__tests__/code-file-editor.spec.tsx b/web/app/components/workflow/skill/editor/__tests__/code-file-editor.spec.tsx
new file mode 100644
index 00000000000..b17f834ad83
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/__tests__/code-file-editor.spec.tsx
@@ -0,0 +1,136 @@
+import type { ReactNode } from 'react'
+import { act, render, screen } from '@testing-library/react'
+
+import CodeFileEditor from '../code-file-editor'
+
+const mocks = vi.hoisted(() => {
+  const editor = {
+    focus: vi.fn(),
+  }
+
+  return {
+    editor,
+    onChange: vi.fn(),
+    onMount: vi.fn(),
+    onAutoFocus: vi.fn(),
+    overlay: null as ReactNode,
+    useSkillCodeCursors: vi.fn(),
+  }
+})
+
+vi.mock('@monaco-editor/react', () => ({
+  default: ({
+    onMount,
+    onChange,
+    loading,
+  }: {
+    onMount: (editor: typeof mocks.editor, monaco: { editor: { setTheme: (theme: string) => void } }) => void
+    onChange: (value: string | undefined) => void
+    loading: ReactNode
+  }) => (
+    <div>
+      <button type="button" onClick={() => onMount(mocks.editor, { editor: { setTheme: vi.fn() } })}>
+        mount-editor
+      </button>
+      <button type="button" onClick={() => onChange('next value')}>
+        change-editor
+      </button>
+      <div data-testid="editor-loading">{loading}</div>
+    </div>
+  ),
+}))
+
+vi.mock('../code-editor/plugins/remote-cursors', () => ({
+  useSkillCodeCursors: (props: unknown) => {
+    mocks.useSkillCodeCursors(props)
+    return { overlay: mocks.overlay }
+  },
+}))
+
+describe('CodeFileEditor', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.overlay = null
+    vi.stubGlobal('requestAnimationFrame', (callback: FrameRequestCallback) => {
+      callback(0)
+      return 1
+    })
+  })
+
+  it('should wire Monaco changes and cursor overlay state', () => {
+    mocks.overlay = <div data-testid="cursor-overlay">overlay</div>
+
+    render(
+      <CodeFileEditor
+        language="typescript"
+        theme="light"
+        value="const a = 1"
+        onChange={mocks.onChange}
+        onMount={mocks.onMount}
+        fileId="file-1"
+        collaborationEnabled
+      />,
+    )
+
+    act(() => {
+      screen.getByRole('button', { name: 'change-editor' }).click()
+    })
+
+    expect(mocks.onChange).toHaveBeenCalledWith('next value')
+    expect(screen.getByTestId('cursor-overlay')).toBeInTheDocument()
+    expect(mocks.useSkillCodeCursors).toHaveBeenCalledWith({
+      editor: null,
+      fileId: 'file-1',
+      enabled: true,
+    })
+  })
+
+  it('should focus the editor after mount when auto focus is enabled', () => {
+    render(
+      <CodeFileEditor
+        language="typescript"
+        theme="light"
+        value="const a = 1"
+        onChange={mocks.onChange}
+        onMount={mocks.onMount}
+        autoFocus
+        onAutoFocus={mocks.onAutoFocus}
+      />,
+    )
+
+    act(() => {
+      screen.getByRole('button', { name: 'mount-editor' }).click()
+    })
+
+    expect(mocks.onMount).toHaveBeenCalled()
+    expect(mocks.editor.focus).toHaveBeenCalledTimes(1)
+    expect(mocks.onAutoFocus).toHaveBeenCalledTimes(1)
+  })
+
+  it('should skip auto focus and collaboration overlay in read only mode', () => {
+    render(
+      <CodeFileEditor
+        language="typescript"
+        theme="light"
+        value="const a = 1"
+        onChange={mocks.onChange}
+        onMount={mocks.onMount}
+        autoFocus
+        fileId="file-1"
+        collaborationEnabled
+        readOnly
+      />,
+    )
+
+    act(() => {
+      screen.getByRole('button', { name: 'mount-editor' }).click()
+    })
+
+    expect(mocks.editor.focus).not.toHaveBeenCalled()
+    expect(mocks.useSkillCodeCursors).toHaveBeenCalledWith({
+      editor: null,
+      fileId: 'file-1',
+      enabled: false,
+    })
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/__tests__/markdown-file-editor.spec.tsx b/web/app/components/workflow/skill/editor/__tests__/markdown-file-editor.spec.tsx
new file mode 100644
index 00000000000..f642be7fdb4
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/__tests__/markdown-file-editor.spec.tsx
@@ -0,0 +1,100 @@
+import { act, render, screen } from '@testing-library/react'
+
+import MarkdownFileEditor from '../markdown-file-editor'
+
+const mocks = vi.hoisted(() => ({
+  onChange: vi.fn(),
+  onAutoFocus: vi.fn(),
+  skillEditorProps: [] as Array<Record<string, unknown>>,
+}))
+
+vi.mock('react-i18next', () => ({
+  useTranslation: () => ({
+    t: (key: string) => key,
+  }),
+}))
+
+vi.mock('../skill-editor', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.skillEditorProps.push(props)
+    return (
+      <div>
+        <button type="button" onClick={() => (props.onChange as (value: string) => void)('updated')}>
+          emit-change
+        </button>
+        <button type="button" onClick={() => (props.onChange as (value: string) => void)(String(props.value))}>
+          emit-same-value
+        </button>
+        <div data-testid="skill-editor-props" />
+      </div>
+    )
+  },
+}))
+
+describe('MarkdownFileEditor', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.skillEditorProps.length = 0
+  })
+
+  it('should pass editable collaboration props and only emit changed values', () => {
+    render(
+      <MarkdownFileEditor
+        instanceId="file-1"
+        value="hello"
+        onChange={mocks.onChange}
+        autoFocus
+        onAutoFocus={mocks.onAutoFocus}
+        collaborationEnabled
+      />,
+    )
+
+    act(() => {
+      screen.getByRole('button', { name: 'emit-change' }).click()
+    })
+
+    expect(mocks.onChange).toHaveBeenCalledWith('updated')
+    expect(mocks.skillEditorProps[0]).toMatchObject({
+      instanceId: 'file-1',
+      value: 'hello',
+      editable: true,
+      autoFocus: true,
+      collaborationEnabled: true,
+      showLineNumbers: true,
+    })
+  })
+
+  it('should disable editing features and placeholder in read only mode', () => {
+    render(
+      <MarkdownFileEditor
+        value="hello"
+        onChange={mocks.onChange}
+        autoFocus
+        collaborationEnabled
+        readOnly
+      />,
+    )
+
+    expect(mocks.skillEditorProps[0]).toMatchObject({
+      editable: false,
+      autoFocus: false,
+      collaborationEnabled: false,
+      placeholder: undefined,
+    })
+  })
+
+  it('should ignore editor updates that do not change the value', () => {
+    render(
+      <MarkdownFileEditor
+        value="hello"
+        onChange={mocks.onChange}
+      />,
+    )
+
+    act(() => {
+      screen.getByRole('button', { name: 'emit-same-value' }).click()
+    })
+
+    expect(mocks.onChange).not.toHaveBeenCalled()
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/code-editor/plugins/__tests__/remote-cursors.spec.tsx b/web/app/components/workflow/skill/editor/code-editor/plugins/__tests__/remote-cursors.spec.tsx
new file mode 100644
index 00000000000..f9c2ca7dab8
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/code-editor/plugins/__tests__/remote-cursors.spec.tsx
@@ -0,0 +1,35 @@
+import { renderHook } from '@testing-library/react'
+import { useSkillCodeCursors } from '../remote-cursors'
+
+vi.mock('@/context/app-context', () => ({
+  useAppContext: () => ({
+    userProfile: {
+      id: 'user-1',
+    },
+  }),
+}))
+
+vi.mock('@/app/components/workflow/collaboration/core/collaboration-manager', () => ({
+  collaborationManager: {
+    onOnlineUsersUpdate: () => vi.fn(),
+  },
+}))
+
+vi.mock('@/app/components/workflow/collaboration/skills/skill-collaboration-manager', () => ({
+  skillCollaborationManager: {
+    onCursorUpdate: () => vi.fn(),
+    emitCursorUpdate: vi.fn(),
+  },
+}))
+
+describe('useSkillCodeCursors', () => {
+  it('should return a null overlay when the hook is disabled', () => {
+    const { result } = renderHook(() => useSkillCodeCursors({
+      editor: null,
+      fileId: 'file-1',
+      enabled: false,
+    }))
+
+    expect(result.current.overlay).toBeNull()
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/__tests__/index.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/__tests__/index.spec.tsx
new file mode 100644
index 00000000000..f68e01d10d7
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/__tests__/index.spec.tsx
@@ -0,0 +1,220 @@
+import { render, screen, waitFor } from '@testing-library/react'
+import * as React from 'react'
+import SkillEditor from '../index'
+
+const mocks = vi.hoisted(() => {
+  const rootElement = document.createElement('div')
+  rootElement.focus = vi.fn()
+
+  return {
+    initialConfig: null as Record<string, unknown> | null,
+    filePreviewValues: [] as Array<Record<string, unknown>>,
+    onBlurProps: [] as Array<Record<string, unknown>>,
+    updateBlockProps: [] as Array<Record<string, unknown>>,
+    localCursorProps: [] as Array<Record<string, unknown>>,
+    remoteCursorProps: [] as Array<Record<string, unknown>>,
+    toolPickerScopes: [] as string[],
+    onChangeCalls: 0,
+    rootElement,
+    editor: {
+      focus: (callback: () => void) => callback(),
+      getRootElement: () => rootElement,
+    },
+  }
+})
+
+vi.mock('@lexical/react/LexicalComposer', () => ({
+  LexicalComposer: ({ initialConfig, children }: { initialConfig: Record<string, unknown>, children: React.ReactNode }) => {
+    mocks.initialConfig = initialConfig
+    return <div data-testid="lexical-composer">{children}</div>
+  },
+}))
+
+vi.mock('@lexical/react/LexicalComposerContext', () => ({
+  useLexicalComposerContext: () => [mocks.editor],
+}))
+
+vi.mock('@lexical/react/LexicalContentEditable', () => ({
+  ContentEditable: (props: Record<string, unknown>) => <div data-testid="content-editable">{JSON.stringify(props)}</div>,
+}))
+
+vi.mock('@lexical/react/LexicalRichTextPlugin', () => ({
+  RichTextPlugin: ({ contentEditable, placeholder }: { contentEditable: React.ReactNode, placeholder: React.ReactNode }) => (
+    <div data-testid="rich-text-plugin">
+      {contentEditable}
+      {placeholder}
+    </div>
+  ),
+}))
+
+vi.mock('@lexical/react/LexicalOnChangePlugin', () => ({
+  OnChangePlugin: ({ onChange }: { onChange: (editorState: { read: (reader: () => unknown) => unknown }) => void }) => {
+    React.useEffect(() => {
+      if (mocks.onChangeCalls === 0) {
+        mocks.onChangeCalls += 1
+        onChange({
+          read: reader => reader(),
+        })
+      }
+    }, [onChange])
+    return <div data-testid="on-change-plugin" />
+  },
+}))
+
+vi.mock('@lexical/react/LexicalErrorBoundary', () => ({
+  LexicalErrorBoundary: () => <div data-testid="error-boundary" />,
+}))
+
+vi.mock('@lexical/react/LexicalHistoryPlugin', () => ({
+  HistoryPlugin: () => <div data-testid="history-plugin" />,
+}))
+
+vi.mock('lexical', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('lexical')>()
+  return {
+    ...actual,
+    $getRoot: () => ({
+      getChildren: () => [
+        { getTextContent: () => 'first line' },
+        { getTextContent: () => 'second line' },
+      ],
+    }),
+  }
+})
+
+vi.mock('@/app/components/base/prompt-editor/plugins/placeholder', () => ({
+  default: ({ value }: { value: React.ReactNode }) => <div data-testid="placeholder">{value}</div>,
+}))
+
+vi.mock('@/app/components/base/prompt-editor/plugins/on-blur-or-focus-block', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.onBlurProps.push(props)
+    return <div data-testid="on-blur-block" />
+  },
+}))
+
+vi.mock('@/app/components/base/prompt-editor/plugins/update-block', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.updateBlockProps.push(props)
+    return <div data-testid="update-block" />
+  },
+}))
+
+vi.mock('@/app/components/base/prompt-editor/utils', () => ({
+  textToEditorState: (value: string) => `editor-state:${value}`,
+}))
+
+vi.mock('../plugins/file-picker-block', () => ({
+  default: () => <div data-testid="file-picker-block" />,
+}))
+
+vi.mock('../plugins/file-reference-block/preview-context', () => ({
+  FilePreviewContextProvider: ({ value, children }: { value: Record<string, unknown>, children: React.ReactNode }) => {
+    mocks.filePreviewValues.push(value)
+    return <div data-testid="file-preview-context">{children}</div>
+  },
+}))
+
+vi.mock('../plugins/file-reference-block/replacement-block', () => ({
+  default: () => <div data-testid="file-reference-replacement-block" />,
+}))
+
+vi.mock('../plugins/remote-cursors', () => ({
+  LocalCursorPlugin: (props: Record<string, unknown>) => {
+    mocks.localCursorProps.push(props)
+    return <div data-testid="local-cursor-plugin" />
+  },
+  SkillRemoteCursors: (props: Record<string, unknown>) => {
+    mocks.remoteCursorProps.push(props)
+    return <div data-testid="remote-cursor-plugin" />
+  },
+}))
+
+vi.mock('../plugins/tool-block', () => ({
+  ToolBlock: () => <div data-testid="tool-block-plugin" />,
+  ToolBlockNode: class MockToolBlockNode {},
+  ToolBlockReplacementBlock: () => <div data-testid="tool-block-replacement-block" />,
+  ToolGroupBlockNode: class MockToolGroupBlockNode {},
+  ToolGroupBlockReplacementBlock: () => <div data-testid="tool-group-block-replacement-block" />,
+}))
+
+vi.mock('../plugins/tool-block/tool-picker-block', () => ({
+  default: ({ scope }: { scope: string }) => {
+    mocks.toolPickerScopes.push(scope)
+    return <div data-testid="tool-picker-block">{scope}</div>
+  },
+}))
+
+beforeEach(() => {
+  mocks.initialConfig = null
+  mocks.filePreviewValues.length = 0
+  mocks.onBlurProps.length = 0
+  mocks.updateBlockProps.length = 0
+  mocks.localCursorProps.length = 0
+  mocks.remoteCursorProps.length = 0
+  mocks.toolPickerScopes.length = 0
+  mocks.onChangeCalls = 0
+  vi.mocked(mocks.rootElement.focus).mockClear()
+})
+
+describe('SkillEditor', () => {
+  it('should build the lexical config and render editable plugins', async () => {
+    const onChange = vi.fn()
+    const onAutoFocus = vi.fn()
+
+    render(
+      <SkillEditor
+        instanceId="file-1"
+        value="hello"
+        editable
+        autoFocus
+        collaborationEnabled
+        toolPickerScope="selection"
+        placeholder="Type here"
+        onChange={onChange}
+        onAutoFocus={onAutoFocus}
+      />,
+    )
+
+    expect(mocks.initialConfig).toMatchObject({
+      namespace: 'skill-editor',
+      editable: true,
+      editorState: 'editor-state:hello',
+    })
+    expect(mocks.filePreviewValues[0]).toEqual({ enabled: false })
+    expect(screen.getByTestId('file-picker-block')).toBeInTheDocument()
+    expect(screen.getByTestId('tool-picker-block')).toHaveTextContent('selection')
+    expect(mocks.toolPickerScopes).toEqual(['selection'])
+    expect(mocks.updateBlockProps[0]).toMatchObject({ instanceId: 'file-1' })
+    expect(mocks.localCursorProps[0]).toMatchObject({ fileId: 'file-1', enabled: true })
+    expect(mocks.remoteCursorProps[0]).toMatchObject({ fileId: 'file-1', enabled: true })
+
+    await waitFor(() => {
+      expect(onChange).toHaveBeenCalledWith('first line\nsecond line')
+    })
+    await waitFor(() => {
+      expect(onAutoFocus).toHaveBeenCalledTimes(1)
+    })
+    expect(mocks.rootElement.focus).toHaveBeenCalledWith({ preventScroll: true })
+  })
+
+  it('should skip editable-only plugins in readonly mode', () => {
+    render(
+      <SkillEditor
+        instanceId="file-2"
+        value="readonly"
+        editable={false}
+        collaborationEnabled={false}
+      />,
+    )
+
+    expect(mocks.initialConfig).toMatchObject({
+      editable: false,
+      editorState: 'editor-state:readonly',
+    })
+    expect(screen.queryByTestId('file-picker-block')).not.toBeInTheDocument()
+    expect(screen.queryByTestId('tool-picker-block')).not.toBeInTheDocument()
+    expect(mocks.localCursorProps[0]).toMatchObject({ fileId: 'file-2', enabled: false })
+    expect(mocks.remoteCursorProps[0]).toMatchObject({ fileId: 'file-2', enabled: false })
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/node.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/node.spec.tsx
new file mode 100644
index 00000000000..27fbb19ab13
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/node.spec.tsx
@@ -0,0 +1,111 @@
+import { act, render, screen } from '@testing-library/react'
+import { $createParagraphNode, $getRoot } from 'lexical'
+import {
+  createLexicalTestEditor,
+} from '@/app/components/base/prompt-editor/plugins/test-helpers'
+import {
+  $createFileReferenceNode,
+  $isFileReferenceNode,
+  FileReferenceNode,
+} from '../node'
+import { buildFileReferenceToken } from '../utils'
+
+vi.mock('../component', () => ({
+  default: ({ nodeKey, resourceId }: { nodeKey: string, resourceId: string }) => (
+    <div data-testid="file-reference-block">{`${nodeKey}:${resourceId}`}</div>
+  ),
+}))
+
+const firstResourceId = '11111111-1111-4111-8111-111111111111'
+const secondResourceId = '22222222-2222-4222-8222-222222222222'
+
+describe('FileReferenceNode', () => {
+  it('should expose lexical metadata and serialize its payload', () => {
+    const editor = createLexicalTestEditor('file-reference-node-metadata-test', [FileReferenceNode])
+    let node!: FileReferenceNode
+
+    act(() => {
+      editor.update(() => {
+        node = $createFileReferenceNode({ resourceId: firstResourceId })
+      })
+    })
+
+    const dom = node.createDOM()
+
+    expect(FileReferenceNode.getType()).toBe('file-reference-block')
+    expect(node.isInline()).toBe(true)
+    expect(node.updateDOM()).toBe(false)
+    expect(node.exportJSON()).toEqual({
+      type: 'file-reference-block',
+      version: 1,
+      resourceId: firstResourceId,
+    })
+    expect(node.getTextContent()).toBe(buildFileReferenceToken(firstResourceId))
+    expect($isFileReferenceNode(node)).toBe(true)
+    expect($isFileReferenceNode(null)).toBe(false)
+    expect($isFileReferenceNode(undefined)).toBe(false)
+    expect(dom.tagName).toBe('SPAN')
+    expect(dom).toHaveClass('inline-flex', 'items-center', 'align-middle')
+  })
+
+  it('should clone and import serialized nodes', () => {
+    const editor = createLexicalTestEditor('file-reference-node-clone-test', [FileReferenceNode])
+    let original!: FileReferenceNode
+    let cloned!: FileReferenceNode
+    let imported!: FileReferenceNode
+
+    act(() => {
+      editor.update(() => {
+        original = $createFileReferenceNode({ resourceId: firstResourceId })
+        cloned = FileReferenceNode.clone(original)
+        imported = FileReferenceNode.importJSON({
+          type: 'file-reference-block',
+          version: 1,
+          resourceId: secondResourceId,
+        })
+      })
+    })
+
+    expect(cloned).not.toBe(original)
+    expect(cloned.exportJSON()).toEqual(original.exportJSON())
+    expect(imported.exportJSON()).toEqual({
+      type: 'file-reference-block',
+      version: 1,
+      resourceId: secondResourceId,
+    })
+  })
+
+  it('should decorate and update its resource id inside editor state', () => {
+    const editor = createLexicalTestEditor('file-reference-node-test', [FileReferenceNode])
+    let node!: FileReferenceNode
+    let updatedText = ''
+    let updatedResourceId = ''
+
+    act(() => {
+      editor.update(() => {
+        node = $createFileReferenceNode({ resourceId: firstResourceId })
+      })
+    })
+
+    render(node.decorate())
+
+    expect(screen.getByTestId('file-reference-block')).toHaveTextContent(firstResourceId)
+
+    act(() => {
+      editor.update(() => {
+        const root = $getRoot()
+        const paragraph = $createParagraphNode()
+        const lexicalNode = $createFileReferenceNode({ resourceId: firstResourceId })
+
+        paragraph.append(lexicalNode)
+        root.append(paragraph)
+        lexicalNode.setResourceId(secondResourceId)
+        updatedText = lexicalNode.getTextContent()
+        updatedResourceId = lexicalNode.exportJSON().resourceId
+      })
+    })
+
+    expect(updatedText).toBe(buildFileReferenceToken(secondResourceId))
+    expect(updatedResourceId).toBe(secondResourceId)
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/preview-context.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/preview-context.spec.tsx
new file mode 100644
index 00000000000..1a8147a5a31
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/preview-context.spec.tsx
@@ -0,0 +1,50 @@
+import type { PropsWithChildren } from 'react'
+import { renderHook } from '@testing-library/react'
+import {
+  FilePreviewContextProvider,
+  useFilePreviewContext,
+} from '../preview-context'
+
+describe('FilePreviewContextProvider', () => {
+  it('should fall back to the default disabled state without a provider', () => {
+    const { result } = renderHook(() => useFilePreviewContext(context => context.enabled))
+
+    expect(result.current).toBe(false)
+  })
+
+  it('should expose the full context value and update subscribers', () => {
+    let enabled = true
+    const wrapper = ({ children }: PropsWithChildren) => (
+      <FilePreviewContextProvider value={{ enabled }}>
+        {children}
+      </FilePreviewContextProvider>
+    )
+
+    const { result, rerender } = renderHook(
+      () => useFilePreviewContext(context => context.enabled),
+      { wrapper },
+    )
+
+    expect(result.current).toBe(true)
+
+    enabled = false
+    rerender()
+
+    expect(result.current).toBe(false)
+  })
+
+  it('should treat an undefined provider value as disabled', () => {
+    const wrapper = ({ children }: PropsWithChildren) => (
+      <FilePreviewContextProvider>
+        {children}
+      </FilePreviewContextProvider>
+    )
+
+    const { result } = renderHook(
+      () => useFilePreviewContext(context => context.enabled),
+      { wrapper },
+    )
+
+    expect(result.current).toBe(false)
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/replacement-block.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/replacement-block.spec.tsx
new file mode 100644
index 00000000000..bbd2a8fed4d
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/replacement-block.spec.tsx
@@ -0,0 +1,74 @@
+import { LexicalComposer } from '@lexical/react/LexicalComposer'
+import { render, waitFor } from '@testing-library/react'
+import { CustomTextNode } from '@/app/components/base/prompt-editor/plugins/custom-text/node'
+import {
+  getNodeCount,
+  renderLexicalEditor,
+  setEditorRootText,
+  waitForEditorReady,
+} from '@/app/components/base/prompt-editor/plugins/test-helpers'
+import {
+  FileReferenceNode,
+} from '../node'
+import FileReferenceReplacementBlock from '../replacement-block'
+import { buildFileReferenceToken } from '../utils'
+
+vi.mock('../component', () => ({
+  default: ({ resourceId }: { resourceId: string }) => <div>{resourceId}</div>,
+}))
+
+const resourceId = '11111111-1111-4111-8111-111111111111'
+
+const renderReplacementPlugin = () => {
+  return renderLexicalEditor({
+    namespace: 'file-reference-replacement-plugin-test',
+    nodes: [CustomTextNode, FileReferenceNode],
+    children: <FileReferenceReplacementBlock />,
+  })
+}
+
+describe('FileReferenceReplacementBlock', () => {
+  it('should replace serialized file reference tokens with file reference nodes', async () => {
+    const { getEditor } = renderReplacementPlugin()
+    const editor = await waitForEditorReady(getEditor)
+
+    setEditorRootText(
+      editor,
+      `prefix ${buildFileReferenceToken(resourceId)} suffix`,
+      text => new CustomTextNode(text),
+    )
+
+    await waitFor(() => {
+      expect(getNodeCount(editor, FileReferenceNode)).toBe(1)
+    })
+  })
+
+  it('should leave plain text untouched when no token is present', async () => {
+    const { getEditor } = renderReplacementPlugin()
+    const editor = await waitForEditorReady(getEditor)
+
+    setEditorRootText(editor, 'plain text without tokens', text => new CustomTextNode(text))
+
+    await waitFor(() => {
+      expect(getNodeCount(editor, FileReferenceNode)).toBe(0)
+    })
+  })
+
+  it('should throw when the file reference node is not registered', () => {
+    expect(() => {
+      render(
+        <LexicalComposer
+          initialConfig={{
+            namespace: 'file-reference-replacement-plugin-missing-node-test',
+            onError: (error: Error) => {
+              throw error
+            },
+            nodes: [CustomTextNode],
+          }}
+        >
+          <FileReferenceReplacementBlock />
+        </LexicalComposer>,
+      )
+    }).toThrow('FileReferenceReplacementBlock: FileReferenceNode not registered on editor')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/utils.spec.ts b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/utils.spec.ts
new file mode 100644
index 00000000000..5a5cae88f20
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/file-reference-block/__tests__/utils.spec.ts
@@ -0,0 +1,28 @@
+import {
+  buildFileReferenceToken,
+  getFileReferenceTokenRegexString,
+  parseFileReferenceToken,
+} from '../utils'
+
+const resourceId = '11111111-1111-4111-8111-111111111111'
+
+describe('file-reference utils', () => {
+  it('should expose a regex that matches serialized file tokens', () => {
+    const regex = new RegExp(`^${getFileReferenceTokenRegexString()}$`)
+
+    expect(regex.test(buildFileReferenceToken(resourceId))).toBe(true)
+    expect(regex.test('§[file].[app].[invalid]§')).toBe(false)
+  })
+
+  it('should parse valid file tokens and reject invalid content', () => {
+    expect(parseFileReferenceToken(buildFileReferenceToken(resourceId))).toEqual({
+      resourceId,
+    })
+    expect(parseFileReferenceToken('plain-text')).toBeNull()
+    expect(parseFileReferenceToken('§[file].[app].[short-id]§')).toBeNull()
+  })
+
+  it('should build file reference tokens from resource ids', () => {
+    expect(buildFileReferenceToken(resourceId)).toBe(`§[file].[app].[${resourceId}]§`)
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/hooks/__tests__/use-editor-blur.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/hooks/__tests__/use-editor-blur.spec.tsx
new file mode 100644
index 00000000000..f7438416c96
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/hooks/__tests__/use-editor-blur.spec.tsx
@@ -0,0 +1,73 @@
+import type { LexicalEditor } from 'lexical'
+import { act, renderHook } from '@testing-library/react'
+import {
+  BLUR_COMMAND,
+  COMMAND_PRIORITY_EDITOR,
+  FOCUS_COMMAND,
+} from 'lexical'
+import { useEditorBlur } from '../use-editor-blur'
+
+describe('useEditorBlur', () => {
+  beforeEach(() => {
+    vi.useFakeTimers()
+  })
+
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('should register blur and focus handlers and toggle visibility state', () => {
+    const blurUnregister = vi.fn()
+    const focusUnregister = vi.fn()
+    const registerCommand = vi
+      .fn()
+      .mockReturnValueOnce(blurUnregister)
+      .mockReturnValueOnce(focusUnregister)
+    const editor = {
+      registerCommand,
+    } as unknown as LexicalEditor
+
+    const { result, unmount } = renderHook(() => useEditorBlur(editor))
+
+    expect(result.current.blurHidden).toBe(false)
+    expect(registerCommand).toHaveBeenNthCalledWith(
+      1,
+      BLUR_COMMAND,
+      expect.any(Function),
+      COMMAND_PRIORITY_EDITOR,
+    )
+    expect(registerCommand).toHaveBeenNthCalledWith(
+      2,
+      FOCUS_COMMAND,
+      expect.any(Function),
+      COMMAND_PRIORITY_EDITOR,
+    )
+
+    const blurHandler = registerCommand.mock.calls[0][1] as () => boolean
+    const focusHandler = registerCommand.mock.calls[1][1] as () => boolean
+
+    act(() => {
+      expect(blurHandler()).toBe(false)
+      vi.advanceTimersByTime(199)
+    })
+    expect(result.current.blurHidden).toBe(false)
+
+    act(() => {
+      vi.advanceTimersByTime(1)
+    })
+    expect(result.current.blurHidden).toBe(true)
+
+    act(() => {
+      expect(focusHandler()).toBe(false)
+    })
+    expect(result.current.blurHidden).toBe(false)
+
+    act(() => {
+      blurHandler()
+    })
+    unmount()
+
+    expect(blurUnregister).toHaveBeenCalledTimes(1)
+    expect(focusUnregister).toHaveBeenCalledTimes(1)
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/remote-cursors/__tests__/index.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/remote-cursors/__tests__/index.spec.tsx
new file mode 100644
index 00000000000..4140284f565
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/remote-cursors/__tests__/index.spec.tsx
@@ -0,0 +1,56 @@
+import { render } from '@testing-library/react'
+import { LocalCursorPlugin, SkillRemoteCursors } from '../index'
+
+const mockEditor = {
+  registerCommand: vi.fn(),
+  registerUpdateListener: vi.fn(),
+  getRootElement: vi.fn(() => null),
+  getEditorState: vi.fn(() => ({
+    read: (reader: () => unknown) => reader(),
+  })),
+}
+
+vi.mock('@lexical/react/LexicalComposerContext', () => ({
+  useLexicalComposerContext: () => [mockEditor],
+}))
+
+vi.mock('@/context/app-context', () => ({
+  useAppContext: () => ({
+    userProfile: {
+      id: 'user-1',
+    },
+  }),
+}))
+
+vi.mock('@/app/components/workflow/collaboration/core/collaboration-manager', () => ({
+  collaborationManager: {
+    onOnlineUsersUpdate: () => vi.fn(),
+  },
+}))
+
+vi.mock('@/app/components/workflow/collaboration/skills/skill-collaboration-manager', () => ({
+  skillCollaborationManager: {
+    onCursorUpdate: () => vi.fn(),
+    emitCursorUpdate: vi.fn(),
+  },
+}))
+
+describe('skill editor remote cursors', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('should not register local cursor listeners when collaboration is disabled', () => {
+    const { container } = render(<LocalCursorPlugin fileId="file-1" enabled={false} />)
+
+    expect(container).toBeEmptyDOMElement()
+    expect(mockEditor.registerCommand).not.toHaveBeenCalled()
+    expect(mockEditor.registerUpdateListener).not.toHaveBeenCalled()
+  })
+
+  it('should render no overlay when remote cursors are disabled', () => {
+    const { container } = render(<SkillRemoteCursors fileId="file-1" enabled={false} />)
+
+    expect(container).toBeEmptyDOMElement()
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/index.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/index.spec.tsx
new file mode 100644
index 00000000000..58d1f884ef7
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/index.spec.tsx
@@ -0,0 +1,108 @@
+import { render } from '@testing-library/react'
+
+import {
+  DELETE_TOOL_BLOCK_COMMAND,
+  INSERT_TOOL_BLOCK_COMMAND,
+} from '../commands'
+import {
+  ToolBlock,
+} from '../index'
+
+const mockInsertNodes = vi.hoisted(() => vi.fn())
+const mockCreateToolBlockNode = vi.hoisted(() => vi.fn((payload: unknown) => ({ kind: 'tool-block-node', payload })))
+const mockRegisterCommand = vi.hoisted(() => vi.fn())
+const mockEditor = vi.hoisted(() => ({
+  hasNodes: vi.fn(() => true),
+  registerCommand: mockRegisterCommand,
+}))
+const unregisterFns = vi.hoisted(() => [vi.fn(), vi.fn()])
+
+vi.mock('@lexical/react/LexicalComposerContext', () => ({
+  useLexicalComposerContext: () => [mockEditor],
+}))
+
+vi.mock('@lexical/utils', () => ({
+  mergeRegister: (...callbacks: Array<() => void>) => () => callbacks.forEach(callback => callback()),
+}))
+
+vi.mock('lexical', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('lexical')>()
+  return {
+    ...actual,
+    $insertNodes: mockInsertNodes,
+    COMMAND_PRIORITY_EDITOR: 100,
+  }
+})
+
+vi.mock('../node', () => ({
+  ToolBlockNode: class MockToolBlockNode {},
+  $createToolBlockNode: mockCreateToolBlockNode,
+}))
+
+describe('ToolBlock', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockEditor.hasNodes.mockReturnValue(true)
+    mockRegisterCommand
+      .mockReturnValueOnce(unregisterFns[0])
+      .mockReturnValueOnce(unregisterFns[1])
+  })
+
+  it('should register insert and delete handlers with the editor', () => {
+    render(<ToolBlock />)
+
+    expect(mockEditor.hasNodes).toHaveBeenCalled()
+    expect(mockRegisterCommand).toHaveBeenNthCalledWith(
+      1,
+      INSERT_TOOL_BLOCK_COMMAND,
+      expect.any(Function),
+      100,
+    )
+    expect(mockRegisterCommand).toHaveBeenNthCalledWith(
+      2,
+      DELETE_TOOL_BLOCK_COMMAND,
+      expect.any(Function),
+      100,
+    )
+  })
+
+  it('should create and insert a tool block node when the insert handler runs', () => {
+    render(<ToolBlock />)
+
+    const insertHandler = mockRegisterCommand.mock.calls[0][1] as (payload: unknown) => boolean
+    const payload = {
+      provider: 'openai/tools',
+      tool: 'search',
+      configId: '11111111-1111-4111-8111-111111111111',
+    }
+
+    expect(insertHandler(payload)).toBe(true)
+    expect(mockCreateToolBlockNode).toHaveBeenCalledWith(payload)
+    expect(mockInsertNodes).toHaveBeenCalledWith([
+      { kind: 'tool-block-node', payload },
+    ])
+  })
+
+  it('should return true from the delete handler', () => {
+    render(<ToolBlock />)
+
+    const deleteHandler = mockRegisterCommand.mock.calls[1][1] as () => boolean
+
+    expect(deleteHandler()).toBe(true)
+  })
+
+  it('should unregister command handlers on unmount', () => {
+    const { unmount } = render(<ToolBlock />)
+
+    unmount()
+
+    expect(unregisterFns[0]).toHaveBeenCalledTimes(1)
+    expect(unregisterFns[1]).toHaveBeenCalledTimes(1)
+  })
+
+  it('should throw when the tool block node is not registered', () => {
+    mockEditor.hasNodes.mockReturnValue(false)
+
+    expect(() => render(<ToolBlock />)).toThrow('ToolBlockPlugin: ToolBlockNode not registered on editor')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/node.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/node.spec.tsx
new file mode 100644
index 00000000000..6c6716bc5ac
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/node.spec.tsx
@@ -0,0 +1,103 @@
+import { act, render, screen } from '@testing-library/react'
+import {
+  createLexicalTestEditor,
+} from '@/app/components/base/prompt-editor/plugins/test-helpers'
+import {
+  $createToolBlockNode,
+  $isToolBlockNode,
+  ToolBlockNode,
+} from '../node'
+import { buildToolToken } from '../utils'
+
+vi.mock('../component', () => ({
+  default: (props: Record<string, unknown>) => (
+    <div data-testid="tool-block-component">{JSON.stringify(props)}</div>
+  ),
+}))
+
+const payload = {
+  provider: 'openai/tools',
+  tool: 'search',
+  configId: '11111111-1111-4111-8111-111111111111',
+  label: 'Search',
+  icon: 'ri-search-line',
+  iconDark: {
+    content: 'moon',
+    background: '#000000',
+  },
+}
+
+describe('ToolBlockNode', () => {
+  it('should expose lexical metadata and serialize its payload', () => {
+    const editor = createLexicalTestEditor('tool-block-node-metadata-test', [ToolBlockNode])
+    let node!: ToolBlockNode
+
+    act(() => {
+      editor.update(() => {
+        node = $createToolBlockNode(payload)
+      })
+    })
+
+    const dom = node.createDOM()
+
+    expect(ToolBlockNode.getType()).toBe('tool-block')
+    expect(node.isInline()).toBe(true)
+    expect(node.updateDOM()).toBe(false)
+    expect(node.exportJSON()).toEqual({
+      type: 'tool-block',
+      version: 1,
+      ...payload,
+    })
+    expect(node.getTextContent()).toBe(buildToolToken(payload))
+    expect($isToolBlockNode(node)).toBe(true)
+    expect($isToolBlockNode(null)).toBe(false)
+    expect(dom.tagName).toBe('SPAN')
+    expect(dom).toHaveClass('inline-flex', 'items-center', 'align-middle')
+  })
+
+  it('should clone and import serialized nodes', () => {
+    const editor = createLexicalTestEditor('tool-block-node-clone-test', [ToolBlockNode])
+    let original!: ToolBlockNode
+    let cloned!: ToolBlockNode
+    let imported!: ToolBlockNode
+
+    act(() => {
+      editor.update(() => {
+        original = $createToolBlockNode(payload)
+        cloned = ToolBlockNode.clone(original)
+        imported = ToolBlockNode.importJSON({
+          type: 'tool-block',
+          version: 1,
+          ...payload,
+          label: 'Imported',
+        })
+      })
+    })
+
+    expect(cloned).not.toBe(original)
+    expect(cloned.exportJSON()).toEqual(original.exportJSON())
+    expect(imported.exportJSON()).toEqual({
+      type: 'tool-block',
+      version: 1,
+      ...payload,
+      label: 'Imported',
+    })
+  })
+
+  it('should decorate the node with the tool block component payload', () => {
+    const editor = createLexicalTestEditor('tool-block-node-decorate-test', [ToolBlockNode])
+    let node!: ToolBlockNode
+
+    act(() => {
+      editor.update(() => {
+        node = $createToolBlockNode(payload)
+      })
+    })
+
+    render(node.decorate())
+
+    expect(screen.getByTestId('tool-block-component')).toHaveTextContent('"provider":"openai/tools"')
+    expect(screen.getByTestId('tool-block-component')).toHaveTextContent('"tool":"search"')
+    expect(screen.getByTestId('tool-block-component')).toHaveTextContent('"label":"Search"')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-block-context.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-block-context.spec.tsx
new file mode 100644
index 00000000000..542fed2090f
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-block-context.spec.tsx
@@ -0,0 +1,56 @@
+import type { PropsWithChildren } from 'react'
+import { renderHook } from '@testing-library/react'
+import {
+  ToolBlockContextProvider,
+  useToolBlockContext,
+} from '../tool-block-context'
+
+describe('ToolBlockContextProvider', () => {
+  it('should fall back to a null context without a provider', () => {
+    const { result } = renderHook(() => useToolBlockContext())
+
+    expect(result.current).toBeNull()
+  })
+
+  it('should expose selected values and update subscribers', () => {
+    let value = {
+      nodeId: 'node-1',
+      useModal: true,
+      disableToolBlocks: false,
+    }
+
+    const wrapper = ({ children }: PropsWithChildren) => (
+      <ToolBlockContextProvider value={value}>
+        {children}
+      </ToolBlockContextProvider>
+    )
+
+    const { result, rerender } = renderHook(
+      () => useToolBlockContext(context => context?.nodeId),
+      { wrapper },
+    )
+
+    expect(result.current).toBe('node-1')
+
+    value = {
+      nodeId: 'node-2',
+      useModal: false,
+      disableToolBlocks: true,
+    }
+    rerender()
+
+    expect(result.current).toBe('node-2')
+  })
+
+  it('should treat an undefined provider value as null', () => {
+    const wrapper = ({ children }: PropsWithChildren) => (
+      <ToolBlockContextProvider>
+        {children}
+      </ToolBlockContextProvider>
+    )
+
+    const { result } = renderHook(() => useToolBlockContext(), { wrapper })
+
+    expect(result.current).toBeNull()
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-block-replacement-block.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-block-replacement-block.spec.tsx
new file mode 100644
index 00000000000..df425c1d275
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-block-replacement-block.spec.tsx
@@ -0,0 +1,74 @@
+import { LexicalComposer } from '@lexical/react/LexicalComposer'
+import { render, waitFor } from '@testing-library/react'
+import { CustomTextNode } from '@/app/components/base/prompt-editor/plugins/custom-text/node'
+import {
+  getNodeCount,
+  renderLexicalEditor,
+  setEditorRootText,
+  waitForEditorReady,
+} from '@/app/components/base/prompt-editor/plugins/test-helpers'
+import {
+  ToolBlockNode,
+} from '../node'
+import ToolBlockReplacementBlock from '../tool-block-replacement-block'
+import { buildToolToken } from '../utils'
+
+vi.mock('../component', () => ({
+  default: ({ tool }: { tool: string }) => <div>{tool}</div>,
+}))
+
+const token = buildToolToken({
+  provider: 'openai/tools',
+  tool: 'search',
+  configId: '11111111-1111-4111-8111-111111111111',
+})
+
+const renderReplacementPlugin = () => {
+  return renderLexicalEditor({
+    namespace: 'tool-block-replacement-plugin-test',
+    nodes: [CustomTextNode, ToolBlockNode],
+    children: <ToolBlockReplacementBlock />,
+  })
+}
+
+describe('ToolBlockReplacementBlock', () => {
+  it('should replace serialized tool tokens with tool block nodes', async () => {
+    const { getEditor } = renderReplacementPlugin()
+    const editor = await waitForEditorReady(getEditor)
+
+    setEditorRootText(editor, `prefix ${token} suffix`, text => new CustomTextNode(text))
+
+    await waitFor(() => {
+      expect(getNodeCount(editor, ToolBlockNode)).toBe(1)
+    })
+  })
+
+  it('should leave plain text untouched when no token is present', async () => {
+    const { getEditor } = renderReplacementPlugin()
+    const editor = await waitForEditorReady(getEditor)
+
+    setEditorRootText(editor, 'plain text without tokens', text => new CustomTextNode(text))
+
+    await waitFor(() => {
+      expect(getNodeCount(editor, ToolBlockNode)).toBe(0)
+    })
+  })
+
+  it('should throw when the tool block node is not registered', () => {
+    expect(() => {
+      render(
+        <LexicalComposer
+          initialConfig={{
+            namespace: 'tool-block-replacement-plugin-missing-node-test',
+            onError: (error: Error) => {
+              throw error
+            },
+            nodes: [CustomTextNode],
+          }}
+        >
+          <ToolBlockReplacementBlock />
+        </LexicalComposer>,
+      )
+    }).toThrow('ToolBlockReplacementBlock: ToolBlockNode not registered on editor')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-group-block-node.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-group-block-node.spec.tsx
new file mode 100644
index 00000000000..20d0dede5ba
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-group-block-node.spec.tsx
@@ -0,0 +1,101 @@
+import { act, render, screen } from '@testing-library/react'
+import {
+  createLexicalTestEditor,
+} from '@/app/components/base/prompt-editor/plugins/test-helpers'
+import {
+  $createToolGroupBlockNode,
+  $isToolGroupBlockNode,
+  ToolGroupBlockNode,
+} from '../tool-group-block-node'
+import { buildToolTokenList } from '../utils'
+
+vi.mock('../tool-group-block-component', () => ({
+  default: (props: Record<string, unknown>) => (
+    <div data-testid="tool-group-block-component">{JSON.stringify(props)}</div>
+  ),
+}))
+
+const tools = [
+  {
+    provider: 'openai/tools',
+    tool: 'search',
+    configId: '11111111-1111-4111-8111-111111111111',
+  },
+  {
+    provider: 'anthropic',
+    tool: 'browse',
+    configId: '22222222-2222-4222-8222-222222222222',
+  },
+]
+
+describe('ToolGroupBlockNode', () => {
+  it('should expose lexical metadata and serialize its payload', () => {
+    const editor = createLexicalTestEditor('tool-group-block-node-metadata-test', [ToolGroupBlockNode])
+    let node!: ToolGroupBlockNode
+
+    act(() => {
+      editor.update(() => {
+        node = $createToolGroupBlockNode({ tools })
+      })
+    })
+
+    const dom = node.createDOM()
+
+    expect(ToolGroupBlockNode.getType()).toBe('tool-group-block')
+    expect(node.isInline()).toBe(true)
+    expect(node.updateDOM()).toBe(false)
+    expect(node.exportJSON()).toEqual({
+      type: 'tool-group-block',
+      version: 1,
+      tools,
+    })
+    expect(node.getTextContent()).toBe(buildToolTokenList(tools))
+    expect($isToolGroupBlockNode(node)).toBe(true)
+    expect($isToolGroupBlockNode(null)).toBe(false)
+    expect(dom.tagName).toBe('SPAN')
+    expect(dom).toHaveClass('inline-flex', 'items-center', 'align-middle')
+  })
+
+  it('should clone and import serialized nodes', () => {
+    const editor = createLexicalTestEditor('tool-group-block-node-clone-test', [ToolGroupBlockNode])
+    let original!: ToolGroupBlockNode
+    let cloned!: ToolGroupBlockNode
+    let imported!: ToolGroupBlockNode
+
+    act(() => {
+      editor.update(() => {
+        original = $createToolGroupBlockNode({ tools })
+        cloned = ToolGroupBlockNode.clone(original)
+        imported = ToolGroupBlockNode.importJSON({
+          type: 'tool-group-block',
+          version: 1,
+          tools: tools.slice(0, 1),
+        })
+      })
+    })
+
+    expect(cloned).not.toBe(original)
+    expect(cloned.exportJSON()).toEqual(original.exportJSON())
+    expect(imported.exportJSON()).toEqual({
+      type: 'tool-group-block',
+      version: 1,
+      tools: tools.slice(0, 1),
+    })
+  })
+
+  it('should decorate the node with the tool group payload', () => {
+    const editor = createLexicalTestEditor('tool-group-block-node-decorate-test', [ToolGroupBlockNode])
+    let node!: ToolGroupBlockNode
+
+    act(() => {
+      editor.update(() => {
+        node = $createToolGroupBlockNode({ tools })
+      })
+    })
+
+    render(node.decorate())
+
+    expect(screen.getByTestId('tool-group-block-component')).toHaveTextContent('"provider":"openai/tools"')
+    expect(screen.getByTestId('tool-group-block-component')).toHaveTextContent('"provider":"anthropic"')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-group-block-replacement-block.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-group-block-replacement-block.spec.tsx
new file mode 100644
index 00000000000..d223fb71a4e
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-group-block-replacement-block.spec.tsx
@@ -0,0 +1,79 @@
+import { LexicalComposer } from '@lexical/react/LexicalComposer'
+import { render, waitFor } from '@testing-library/react'
+import { CustomTextNode } from '@/app/components/base/prompt-editor/plugins/custom-text/node'
+import {
+  getNodeCount,
+  renderLexicalEditor,
+  setEditorRootText,
+  waitForEditorReady,
+} from '@/app/components/base/prompt-editor/plugins/test-helpers'
+import { ToolGroupBlockNode } from '../tool-group-block-node'
+import ToolGroupBlockReplacementBlock from '../tool-group-block-replacement-block'
+import { buildToolTokenList } from '../utils'
+
+vi.mock('../tool-group-block-component', () => ({
+  default: ({ tools }: { tools: Array<{ tool: string }> }) => <div>{tools.map(tool => tool.tool).join(',')}</div>,
+}))
+
+const tokenList = buildToolTokenList([
+  {
+    provider: 'openai/tools',
+    tool: 'search',
+    configId: '11111111-1111-4111-8111-111111111111',
+  },
+  {
+    provider: 'anthropic',
+    tool: 'browse',
+    configId: '22222222-2222-4222-8222-222222222222',
+  },
+])
+
+const renderReplacementPlugin = () => {
+  return renderLexicalEditor({
+    namespace: 'tool-group-block-replacement-plugin-test',
+    nodes: [CustomTextNode, ToolGroupBlockNode],
+    children: <ToolGroupBlockReplacementBlock />,
+  })
+}
+
+describe('ToolGroupBlockReplacementBlock', () => {
+  it('should replace serialized tool token lists with tool group nodes', async () => {
+    const { getEditor } = renderReplacementPlugin()
+    const editor = await waitForEditorReady(getEditor)
+
+    setEditorRootText(editor, `prefix ${tokenList} suffix`, text => new CustomTextNode(text))
+
+    await waitFor(() => {
+      expect(getNodeCount(editor, ToolGroupBlockNode)).toBe(1)
+    })
+  })
+
+  it('should leave plain text untouched when no tool token list is present', async () => {
+    const { getEditor } = renderReplacementPlugin()
+    const editor = await waitForEditorReady(getEditor)
+
+    setEditorRootText(editor, 'plain text without tokens', text => new CustomTextNode(text))
+
+    await waitFor(() => {
+      expect(getNodeCount(editor, ToolGroupBlockNode)).toBe(0)
+    })
+  })
+
+  it('should throw when the tool group block node is not registered', () => {
+    expect(() => {
+      render(
+        <LexicalComposer
+          initialConfig={{
+            namespace: 'tool-group-block-replacement-plugin-missing-node-test',
+            onError: (error: Error) => {
+              throw error
+            },
+            nodes: [CustomTextNode],
+          }}
+        >
+          <ToolGroupBlockReplacementBlock />
+        </LexicalComposer>,
+      )
+    }).toThrow('ToolGroupBlockReplacementBlock: ToolGroupBlockNode not registered on editor')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-header.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-header.spec.tsx
new file mode 100644
index 00000000000..8f3f8921642
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/tool-header.spec.tsx
@@ -0,0 +1,84 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import ToolHeader from '../tool-header'
+
+vi.mock('@/app/components/base/app-icon', () => ({
+  default: (props: Record<string, unknown>) => (
+    <div data-testid="app-icon">{JSON.stringify(props)}</div>
+  ),
+}))
+
+describe('ToolHeader', () => {
+  it('should render labels and close action without an icon', () => {
+    const onClose = vi.fn()
+
+    render(
+      <ToolHeader
+        icon={undefined}
+        providerLabel="Provider"
+        toolLabel="Tool"
+        description="Description"
+        onClose={onClose}
+      />,
+    )
+
+    expect(screen.getByText('Provider')).toBeInTheDocument()
+    expect(screen.getByText('Tool')).toBeInTheDocument()
+    expect(screen.getByText('Description')).toBeInTheDocument()
+    expect(screen.queryByTestId('app-icon')).not.toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button'))
+
+    expect(onClose).toHaveBeenCalledTimes(1)
+  })
+
+  it('should render a remote icon and invoke the back action', () => {
+    const onBack = vi.fn()
+
+    const { container } = render(
+      <ToolHeader
+        icon="https://cdn.example.com/icon.png"
+        providerLabel="Provider"
+        toolLabel="Tool"
+        description="Description"
+        onClose={vi.fn()}
+        onBack={onBack}
+        backLabel="Back to tools"
+      />,
+    )
+
+    const remoteIcon = container.querySelector('[style*="background-image"]')
+
+    expect(remoteIcon).toHaveStyle({ backgroundImage: 'url(https://cdn.example.com/icon.png)' })
+
+    fireEvent.click(screen.getByRole('button', { name: 'Back to tools' }))
+
+    expect(onBack).toHaveBeenCalledTimes(1)
+  })
+
+  it('should render app icons for both icon names and emoji payloads', () => {
+    const { rerender } = render(
+      <ToolHeader
+        icon="ri-search-line"
+        providerLabel="Provider"
+        toolLabel="Tool"
+        description="Description"
+        onClose={vi.fn()}
+      />,
+    )
+
+    expect(screen.getByTestId('app-icon')).toHaveTextContent('"icon":"ri-search-line"')
+
+    rerender(
+      <ToolHeader
+        icon={{ content: 'moon', background: '#000000' }}
+        providerLabel="Provider"
+        toolLabel="Tool"
+        description="Description"
+        onClose={vi.fn()}
+      />,
+    )
+
+    expect(screen.getByTestId('app-icon')).toHaveTextContent('"icon":"moon"')
+    expect(screen.getByTestId('app-icon')).toHaveTextContent('"background":"#000000"')
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/utils.spec.ts b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/utils.spec.ts
new file mode 100644
index 00000000000..5df0b32735d
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/plugins/tool-block/__tests__/utils.spec.ts
@@ -0,0 +1,51 @@
+import {
+  buildToolToken,
+  buildToolTokenList,
+  getToolTokenListRegexString,
+  getToolTokenRegexString,
+  parseToolToken,
+  parseToolTokenList,
+} from '../utils'
+
+const firstToken = {
+  provider: 'openai/tools',
+  tool: 'search',
+  configId: '11111111-1111-4111-8111-111111111111',
+}
+
+const secondToken = {
+  provider: 'anthropic',
+  tool: 'browse',
+  configId: '22222222-2222-4222-8222-222222222222',
+}
+
+describe('tool-block utils', () => {
+  it('should expose regexes that match tool tokens and token lists', () => {
+    const tokenRegex = new RegExp(`^${getToolTokenRegexString()}$`)
+    const listRegex = new RegExp(`^${getToolTokenListRegexString()}$`)
+
+    expect(tokenRegex.test(buildToolToken(firstToken))).toBe(true)
+    expect(tokenRegex.test('§[tool].[bad token]§')).toBe(false)
+    expect(listRegex.test(buildToolTokenList([firstToken, secondToken]))).toBe(true)
+  })
+
+  it('should parse tool tokens and token lists', () => {
+    expect(parseToolToken(buildToolToken(firstToken))).toEqual(firstToken)
+    expect(parseToolToken('plain-text')).toBeNull()
+    expect(parseToolTokenList(buildToolTokenList([firstToken, secondToken]))).toEqual([
+      firstToken,
+      secondToken,
+    ])
+    expect(parseToolTokenList('[plain-text')).toBeNull()
+    expect(parseToolTokenList('[]')).toBeNull()
+    expect(parseToolTokenList('[ , ]')).toBeNull()
+    expect(parseToolTokenList('[plain-text]')).toBeNull()
+  })
+
+  it('should build serialized tool tokens and lists', () => {
+    expect(buildToolToken(firstToken)).toBe('§[tool].[openai/tools].[search].[11111111-1111-4111-8111-111111111111]§')
+    expect(buildToolTokenList([firstToken, secondToken])).toBe(
+      `[${buildToolToken(firstToken)},${buildToolToken(secondToken)}]`,
+    )
+  })
+})
diff --git a/web/app/components/workflow/skill/editor/skill-editor/tool-setting/__tests__/tool-settings-section.spec.tsx b/web/app/components/workflow/skill/editor/skill-editor/tool-setting/__tests__/tool-settings-section.spec.tsx
new file mode 100644
index 00000000000..f7e17f2e301
--- /dev/null
+++ b/web/app/components/workflow/skill/editor/skill-editor/tool-setting/__tests__/tool-settings-section.spec.tsx
@@ -0,0 +1,162 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import { FormTypeEnum } from '@/app/components/header/account-setting/model-provider-page/declarations'
+import { VarKindType } from '@/app/components/workflow/nodes/_base/types'
+import ToolSettingsSection from '../tool-settings-section'
+
+const mocks = vi.hoisted(() => ({
+  formProps: [] as Array<Record<string, unknown>>,
+}))
+
+vi.mock('react-i18next', () => ({
+  useTranslation: () => ({
+    t: (key: string) => key,
+  }),
+}))
+
+vi.mock('@/app/components/base/divider', () => ({
+  default: () => <div data-testid="divider" />,
+}))
+
+vi.mock('@/app/components/plugins/plugin-detail-panel/tool-selector/reasoning-config-form', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.formProps.push(props)
+    const variable = (props.schemas as Array<{ variable: string }>)[0]?.variable ?? 'unknown'
+    return (
+      <button
+        type="button"
+        data-testid={`reasoning-form-${variable}`}
+        onClick={() => (props.onChange as (value: Record<string, unknown>) => void)({
+          [variable]: {
+            auto: 0,
+            value: {
+              type: 'constant',
+              value: 'updated',
+            },
+          },
+        })}
+      >
+        {variable}
+      </button>
+    )
+  },
+}))
+
+vi.mock('@/app/components/tools/utils/to-form-schema', () => ({
+  toolParametersToFormSchemas: (params: Array<{ name: string, type: string, default?: unknown }>) => {
+    return params.map(param => ({
+      variable: param.name,
+      type: param.type,
+      default: param.default,
+    }))
+  },
+}))
+
+beforeEach(() => {
+  mocks.formProps.length = 0
+})
+
+describe('ToolSettingsSection', () => {
+  it('should return null when the provider is not team-authorized or when there are no schemas', () => {
+    const { rerender, container } = render(
+      <ToolSettingsSection
+        currentProvider={{ is_team_authorization: false } as never}
+        currentTool={{
+          parameters: [{ name: 'temperature', form: 'basic', type: FormTypeEnum.textInput }],
+        } as never}
+      />,
+    )
+
+    expect(container).toBeEmptyDOMElement()
+
+    rerender(
+      <ToolSettingsSection
+        currentProvider={{ is_team_authorization: true } as never}
+        currentTool={{ parameters: [] } as never}
+      />,
+    )
+
+    expect(container).toBeEmptyDOMElement()
+  })
+
+  it('should build safe config values and merge settings and params changes', () => {
+    const onChange = vi.fn()
+
+    render(
+      <ToolSettingsSection
+        currentProvider={{ is_team_authorization: true } as never}
+        currentTool={{
+          parameters: [
+            { name: 'model', form: 'basic', type: FormTypeEnum.modelSelector, default: 'gpt-4.1' },
+            { name: 'attachment', form: 'llm', type: FormTypeEnum.file, default: null },
+          ],
+        } as never}
+        value={{
+          provider_id: 'provider-1',
+          tool_name: 'tool-1',
+          settings: {},
+          parameters: {},
+        } as never}
+        enableVariableReference
+        nodesOutputVars={[]}
+        availableNodes={[]}
+        onChange={onChange}
+      />,
+    )
+
+    expect(screen.getByTestId('divider')).toBeInTheDocument()
+    expect(screen.getByText('detailPanel.toolSelector.reasoningConfig')).toBeInTheDocument()
+    expect(mocks.formProps).toHaveLength(2)
+    expect(mocks.formProps[0]).toMatchObject({
+      nodeId: 'workflow',
+      disableVariableReference: false,
+      value: {
+        model: {
+          auto: 0,
+          value: {
+            type: VarKindType.constant,
+            value: 'gpt-4.1',
+          },
+        },
+      },
+    })
+    expect(mocks.formProps[1]).toMatchObject({
+      nodeId: 'workflow',
+      disableVariableReference: false,
+      value: {
+        attachment: {
+          auto: 1,
+          value: {
+            type: VarKindType.variable,
+            value: null,
+          },
+        },
+      },
+    })
+
+    fireEvent.click(screen.getByTestId('reasoning-form-model'))
+    fireEvent.click(screen.getByTestId('reasoning-form-attachment'))
+
+    expect(onChange).toHaveBeenNthCalledWith(1, expect.objectContaining({
+      settings: {
+        model: {
+          auto: 0,
+          value: {
+            type: 'constant',
+            value: 'updated',
+          },
+        },
+      },
+    }))
+    expect(onChange).toHaveBeenNthCalledWith(2, expect.objectContaining({
+      parameters: {
+        attachment: {
+          auto: 0,
+          value: {
+            type: 'constant',
+            value: 'updated',
+          },
+        },
+      },
+    }))
+  })
+})
diff --git a/web/app/components/workflow/skill/file-tree/artifacts/artifacts-section.spec.tsx b/web/app/components/workflow/skill/file-tree/artifacts/__tests__/artifacts-section.spec.tsx
similarity index 92%
rename from web/app/components/workflow/skill/file-tree/artifacts/artifacts-section.spec.tsx
rename to web/app/components/workflow/skill/file-tree/artifacts/__tests__/artifacts-section.spec.tsx
index abb5b1076da..6a8ec9f8553 100644
--- a/web/app/components/workflow/skill/file-tree/artifacts/artifacts-section.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/artifacts/__tests__/artifacts-section.spec.tsx
@@ -1,6 +1,6 @@
 import type { SandboxFileDownloadTicket, SandboxFileNode } from '@/types/sandbox-file'
 import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import ArtifactsSection from './artifacts-section'
+import ArtifactsSection from '.././artifacts-section'
 
 type MockStoreState = {
   appId: string | undefined
@@ -12,7 +12,7 @@ const mocks = vi.hoisted(() => ({
     appId: 'app-1',
     selectedArtifactPath: null,
   } as MockStoreState,
-  flatData: [] as SandboxFileNode[],
+  flatData: undefined as SandboxFileNode[] | undefined,
   isLoading: false,
   isDownloading: false,
   selectArtifact: vi.fn(),
@@ -66,7 +66,7 @@ describe('ArtifactsSection', () => {
     vi.clearAllMocks()
     mocks.storeState.appId = 'app-1'
     mocks.storeState.selectedArtifactPath = null
-    mocks.flatData = []
+    mocks.flatData = undefined
     mocks.isLoading = false
     mocks.isDownloading = false
     mocks.fetchDownloadUrl.mockResolvedValue({
@@ -119,6 +119,7 @@ describe('ArtifactsSection', () => {
   // Covers expanded branches for empty and loading states.
   describe('Expanded content', () => {
     it('should render empty state when expanded and there are no files', () => {
+      mocks.flatData = []
       render(<ArtifactsSection />)
 
       fireEvent.click(screen.getByRole('button', { name: /workflow\.skillSidebar\.artifacts\.openArtifacts/i }))
@@ -134,6 +135,15 @@ describe('ArtifactsSection', () => {
 
       expect(screen.queryByText('workflow.skillSidebar.artifacts.emptyState')).not.toBeInTheDocument()
     })
+
+    it('should treat an undefined query result as an empty tree', () => {
+      render(<ArtifactsSection />)
+
+      fireEvent.click(screen.getByRole('button', { name: /workflow\.skillSidebar\.artifacts\.openArtifacts/i }))
+
+      expect(screen.getByText('workflow.skillSidebar.artifacts.emptyState')).toBeInTheDocument()
+      expect(document.querySelector('.bg-state-accent-solid')).not.toBeInTheDocument()
+    })
   })
 
   // Covers real tree integration for selecting and downloading artifacts.
diff --git a/web/app/components/workflow/skill/file-tree/artifacts/artifacts-tree.spec.tsx b/web/app/components/workflow/skill/file-tree/artifacts/__tests__/artifacts-tree.spec.tsx
similarity index 99%
rename from web/app/components/workflow/skill/file-tree/artifacts/artifacts-tree.spec.tsx
rename to web/app/components/workflow/skill/file-tree/artifacts/__tests__/artifacts-tree.spec.tsx
index 09389268418..1982cc7010d 100644
--- a/web/app/components/workflow/skill/file-tree/artifacts/artifacts-tree.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/artifacts/__tests__/artifacts-tree.spec.tsx
@@ -1,6 +1,6 @@
 import type { SandboxFileTreeNode } from '@/types/sandbox-file'
 import { fireEvent, render, screen } from '@testing-library/react'
-import ArtifactsTree from './artifacts-tree'
+import ArtifactsTree from '.././artifacts-tree'
 
 const createNode = (overrides: Partial<SandboxFileTreeNode> = {}): SandboxFileTreeNode => ({
   id: 'node-1',
diff --git a/web/app/components/workflow/skill/file-tree/artifacts/__tests__/utils.spec.ts b/web/app/components/workflow/skill/file-tree/artifacts/__tests__/utils.spec.ts
new file mode 100644
index 00000000000..786ff1b23ef
--- /dev/null
+++ b/web/app/components/workflow/skill/file-tree/artifacts/__tests__/utils.spec.ts
@@ -0,0 +1,62 @@
+import { buildTreeFromFlatList } from '../utils'
+
+describe('artifacts utils', () => {
+  it('should build nested tree nodes from a flat node list', () => {
+    const tree = buildTreeFromFlatList([
+      {
+        path: 'folder',
+        is_dir: true,
+        size: 0,
+        mtime: 1,
+        extension: null,
+      },
+      {
+        path: 'folder/readme.md',
+        is_dir: false,
+        size: 12,
+        mtime: 2,
+        extension: 'md',
+      },
+      {
+        path: 'logo.png',
+        is_dir: false,
+        size: 3,
+        mtime: 3,
+        extension: 'png',
+      },
+    ])
+
+    expect(tree).toEqual([
+      expect.objectContaining({
+        id: 'folder',
+        node_type: 'folder',
+        children: [
+          expect.objectContaining({
+            id: 'folder/readme.md',
+            node_type: 'file',
+            extension: 'md',
+          }),
+        ],
+      }),
+      expect.objectContaining({
+        id: 'logo.png',
+        node_type: 'file',
+        children: [],
+      }),
+    ])
+  })
+
+  it('should skip nodes whose parent path does not exist in the flat list', () => {
+    const tree = buildTreeFromFlatList([
+      {
+        path: 'missing-parent/readme.md',
+        is_dir: false,
+        size: 7,
+        mtime: 1,
+        extension: 'md',
+      },
+    ])
+
+    expect(tree).toEqual([])
+  })
+})
diff --git a/web/app/components/workflow/skill/file-tree/tree/drag-action-tooltip.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/drag-action-tooltip.spec.tsx
similarity index 94%
rename from web/app/components/workflow/skill/file-tree/tree/drag-action-tooltip.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/drag-action-tooltip.spec.tsx
index 6e126e145c1..843f826373c 100644
--- a/web/app/components/workflow/skill/file-tree/tree/drag-action-tooltip.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/drag-action-tooltip.spec.tsx
@@ -1,7 +1,7 @@
 import type { AppAssetTreeView } from '@/types/app-asset'
 import { render, screen } from '@testing-library/react'
-import { ROOT_ID } from '../../constants'
-import DragActionTooltip from './drag-action-tooltip'
+import { ROOT_ID } from '../../../constants'
+import DragActionTooltip from '.././drag-action-tooltip'
 
 type MockWorkflowState = {
   dragOverFolderId: string | null
@@ -18,7 +18,7 @@ vi.mock('@/app/components/workflow/store', () => ({
   useStore: (selector: (state: MockWorkflowState) => unknown) => selector(mocks.storeState),
 }))
 
-vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useSkillAssetNodeMap: () => ({ data: mocks.nodeMap }),
 }))
 
diff --git a/web/app/components/workflow/skill/file-tree/tree/file-tree.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/file-tree.spec.tsx
similarity index 94%
rename from web/app/components/workflow/skill/file-tree/tree/file-tree.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/file-tree.spec.tsx
index fa6a60bfd84..b370a271d58 100644
--- a/web/app/components/workflow/skill/file-tree/tree/file-tree.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/file-tree.spec.tsx
@@ -1,8 +1,8 @@
 import type { HTMLAttributes, ReactNode, Ref } from 'react'
 import type { AppAssetTreeView } from '@/types/app-asset'
 import { fireEvent, render, screen } from '@testing-library/react'
-import { ROOT_ID } from '../../constants'
-import FileTree from './file-tree'
+import { ROOT_ID } from '../../../constants'
+import FileTree from '.././file-tree'
 
 type MockWorkflowState = {
   expandedFolderIds: Set<string>
@@ -216,66 +216,66 @@ vi.mock('@/app/components/workflow/store', () => ({
   }),
 }))
 
-vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useSkillAssetTreeData: () => mocks.skillAssetTreeData,
 }))
 
-vi.mock('../../hooks/file-tree/data/use-skill-tree-collaboration', () => ({
+vi.mock('../../../hooks/file-tree/data/use-skill-tree-collaboration', () => ({
   useSkillTreeCollaboration: () => mocks.useSkillTreeCollaboration(),
 }))
 
-vi.mock('../../hooks/file-tree/dnd/use-root-file-drop', () => ({
+vi.mock('../../../hooks/file-tree/dnd/use-root-file-drop', () => ({
   useRootFileDrop: () => mocks.rootDropHandlers,
 }))
 
-vi.mock('../../hooks/file-tree/interaction/use-inline-create-node', () => ({
+vi.mock('../../../hooks/file-tree/interaction/use-inline-create-node', () => ({
   useInlineCreateNode: () => mocks.inlineCreateNode,
 }))
 
-vi.mock('../../hooks/file-tree/interaction/use-skill-shortcuts', () => ({
+vi.mock('../../../hooks/file-tree/interaction/use-skill-shortcuts', () => ({
   useSkillShortcuts: (args: unknown) => mocks.useSkillShortcuts(args),
 }))
 
-vi.mock('../../hooks/file-tree/interaction/use-sync-tree-with-active-tab', () => ({
+vi.mock('../../../hooks/file-tree/interaction/use-sync-tree-with-active-tab', () => ({
   useSyncTreeWithActiveTab: (args: unknown) => mocks.useSyncTreeWithActiveTab(args),
 }))
 
-vi.mock('../../hooks/file-tree/operations/use-node-move', () => ({
+vi.mock('../../../hooks/file-tree/operations/use-node-move', () => ({
   useNodeMove: () => ({ executeMoveNode: mocks.executeMoveNode }),
 }))
 
-vi.mock('../../hooks/file-tree/operations/use-node-reorder', () => ({
+vi.mock('../../../hooks/file-tree/operations/use-node-reorder', () => ({
   useNodeReorder: () => ({ executeReorderNode: mocks.executeReorderNode }),
 }))
 
-vi.mock('../../hooks/file-tree/operations/use-paste-operation', () => ({
+vi.mock('../../../hooks/file-tree/operations/use-paste-operation', () => ({
   usePasteOperation: (args: unknown) => mocks.usePasteOperation(args),
 }))
 
-vi.mock('../../utils/tree-utils', () => ({
+vi.mock('../../../utils/tree-utils', () => ({
   isDescendantOf: (parentId: string, nodeId: string, treeChildren: AppAssetTreeView[]) =>
     mocks.isDescendantOf(parentId, nodeId, treeChildren),
 }))
 
-vi.mock('./search-result-list', () => ({
+vi.mock('.././search-result-list', () => ({
   default: ({ searchTerm }: { searchTerm: string }) => (
     <div data-testid="search-result-list">{searchTerm}</div>
   ),
 }))
 
-vi.mock('./drag-action-tooltip', () => ({
+vi.mock('.././drag-action-tooltip', () => ({
   default: ({ action }: { action: string }) => (
     <div data-testid="drag-action-tooltip">{action}</div>
   ),
 }))
 
-vi.mock('./upload-status-tooltip', () => ({
+vi.mock('.././upload-status-tooltip', () => ({
   default: ({ fallback }: { fallback?: ReactNode }) => (
     <div data-testid="upload-status-tooltip">{fallback}</div>
   ),
 }))
 
-vi.mock('./tree-context-menu', () => ({
+vi.mock('.././tree-context-menu', () => ({
   default: ({
     children,
     treeRef,
diff --git a/web/app/components/workflow/skill/file-tree/tree/menu-item.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/menu-item.spec.tsx
similarity index 93%
rename from web/app/components/workflow/skill/file-tree/tree/menu-item.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/menu-item.spec.tsx
index 9550afa649b..686f95d627b 100644
--- a/web/app/components/workflow/skill/file-tree/tree/menu-item.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/menu-item.spec.tsx
@@ -1,4 +1,4 @@
-import type { MenuItemProps } from './menu-item'
+import type { MenuItemProps } from '.././menu-item'
 import { fireEvent, render, screen } from '@testing-library/react'
 import {
   ContextMenu,
@@ -10,7 +10,7 @@ import {
   DropdownMenuContent,
   DropdownMenuTrigger,
 } from '@/app/components/base/ui/dropdown-menu'
-import MenuItem from './menu-item'
+import MenuItem from '.././menu-item'
 
 const MockIcon = (props: React.SVGProps<SVGSVGElement>) => <svg {...props} />
 
@@ -67,6 +67,12 @@ describe('MenuItem', () => {
       expect(item).not.toHaveClass('w-full')
     })
 
+    it('should render inside the context menu variant', () => {
+      renderMenuItem({ menuType: 'context', label: 'Reveal' })
+
+      expect(screen.getByRole('menuitem', { name: /reveal/i })).toBeInTheDocument()
+    })
+
     it('should apply destructive variant styles when variant is destructive', () => {
       // Arrange
       renderMenuItem({ variant: 'destructive', label: 'Delete' })
diff --git a/web/app/components/workflow/skill/file-tree/tree/__tests__/node-delete-confirm-dialog.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/node-delete-confirm-dialog.spec.tsx
new file mode 100644
index 00000000000..fbbf59e5c10
--- /dev/null
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/node-delete-confirm-dialog.spec.tsx
@@ -0,0 +1,48 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import NodeDeleteConfirmDialog from '../node-delete-confirm-dialog'
+
+describe('NodeDeleteConfirmDialog', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('should render the file deletion copy and call confirm/cancel handlers', () => {
+    const onConfirm = vi.fn()
+    const onCancel = vi.fn()
+
+    render(
+      <NodeDeleteConfirmDialog
+        nodeType="file"
+        open
+        isDeleting={false}
+        onConfirm={onConfirm}
+        onCancel={onCancel}
+      />,
+    )
+
+    expect(screen.getByText('workflow.skillSidebar.menu.fileDeleteConfirmTitle')).toBeInTheDocument()
+    expect(screen.getByText('workflow.skillSidebar.menu.fileDeleteConfirmContent')).toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button', { name: /common\.operation\.confirm/i }))
+    expect(onConfirm).toHaveBeenCalledTimes(1)
+
+    fireEvent.click(screen.getByRole('button', { name: /common\.operation\.cancel/i }))
+    expect(onCancel).toHaveBeenCalledTimes(1)
+  })
+
+  it('should render the folder deletion copy and disable confirm while deleting', () => {
+    render(
+      <NodeDeleteConfirmDialog
+        nodeType="folder"
+        open
+        isDeleting
+        onConfirm={vi.fn()}
+        onCancel={vi.fn()}
+      />,
+    )
+
+    expect(screen.getByText('workflow.skillSidebar.menu.deleteConfirmTitle')).toBeInTheDocument()
+    expect(screen.getByText('workflow.skillSidebar.menu.deleteConfirmContent')).toBeInTheDocument()
+    expect(screen.getByRole('button', { name: /common\.operation\.confirm/i })).toBeDisabled()
+  })
+})
diff --git a/web/app/components/workflow/skill/file-tree/tree/node-menu.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/node-menu.spec.tsx
similarity index 99%
rename from web/app/components/workflow/skill/file-tree/tree/node-menu.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/node-menu.spec.tsx
index f6bd486ea20..c7e27fb8d30 100644
--- a/web/app/components/workflow/skill/file-tree/tree/node-menu.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/node-menu.spec.tsx
@@ -10,8 +10,8 @@ import {
   DropdownMenuContent,
   DropdownMenuTrigger,
 } from '@/app/components/base/ui/dropdown-menu'
-import { NODE_MENU_TYPE } from '../../constants'
-import NodeMenu from './node-menu'
+import { NODE_MENU_TYPE } from '../../../constants'
+import NodeMenu from '.././node-menu'
 
 type MockWorkflowState = {
   hasClipboard: () => boolean
diff --git a/web/app/components/workflow/skill/file-tree/tree/search-result-list.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/search-result-list.spec.tsx
similarity index 99%
rename from web/app/components/workflow/skill/file-tree/tree/search-result-list.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/search-result-list.spec.tsx
index c018af096f5..224ab81c4a6 100644
--- a/web/app/components/workflow/skill/file-tree/tree/search-result-list.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/search-result-list.spec.tsx
@@ -1,6 +1,6 @@
 import type { AppAssetTreeView } from '@/types/app-asset'
 import { fireEvent, render, screen } from '@testing-library/react'
-import SearchResultList from './search-result-list'
+import SearchResultList from '.././search-result-list'
 
 type MockWorkflowState = {
   activeTabId: string | null
diff --git a/web/app/components/workflow/skill/file-tree/tree/tree-context-menu.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-context-menu.spec.tsx
similarity index 66%
rename from web/app/components/workflow/skill/file-tree/tree/tree-context-menu.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/tree-context-menu.spec.tsx
index 63cf90d3e94..801421c69de 100644
--- a/web/app/components/workflow/skill/file-tree/tree/tree-context-menu.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-context-menu.spec.tsx
@@ -1,6 +1,6 @@
 import { fireEvent, render, screen } from '@testing-library/react'
-import { ROOT_ID } from '../../constants'
-import TreeContextMenu from './tree-context-menu'
+import { ROOT_ID } from '../../../constants'
+import TreeContextMenu from '.././tree-context-menu'
 
 const mocks = vi.hoisted(() => ({
   selectedNodeIds: new Set<string>(),
@@ -10,6 +10,7 @@ const mocks = vi.hoisted(() => ({
   getNode: vi.fn(),
   selectNode: vi.fn(),
   useFileOperations: vi.fn(),
+  dynamicImporters: [] as Array<() => Promise<unknown>>,
   fileOperations: {
     fileInputRef: { current: null },
     folderInputRef: { current: null },
@@ -38,8 +39,9 @@ vi.mock('@/app/components/workflow/store', () => ({
   }),
 }))
 
-vi.mock('next/dynamic', () => ({
-  default: () => {
+vi.mock('@/next/dynamic', () => ({
+  default: (loader: () => Promise<unknown>) => {
+    mocks.dynamicImporters.push(loader)
     const MockImportSkillModal = ({ isOpen, onClose }: { isOpen: boolean, onClose: () => void }) => {
       if (!isOpen)
         return null
@@ -57,15 +59,30 @@ vi.mock('next/dynamic', () => ({
   },
 }))
 
-vi.mock('../../hooks/file-tree/operations/use-file-operations', () => ({
+vi.mock('../../start-tab/import-skill-modal', () => ({
+  default: ({ isOpen, onClose }: { isOpen: boolean, onClose: () => void }) => {
+    if (!isOpen)
+      return null
+
+    return (
+      <div data-testid="resolved-import-skill-modal">
+        <button type="button" onClick={onClose}>
+          resolved-close-import-modal
+        </button>
+      </div>
+    )
+  },
+}))
+
+vi.mock('../../../hooks/file-tree/operations/use-file-operations', () => ({
   useFileOperations: (...args: unknown[]) => {
     mocks.useFileOperations(...args)
     return mocks.fileOperations
   },
 }))
 
-vi.mock('./node-menu', () => ({
-  default: ({ type, menuType, nodeId, actionNodeIds, onImportSkills }: { type: string, menuType: string, nodeId?: string, actionNodeIds?: string[], onImportSkills?: () => void }) => (
+vi.mock('.././node-menu', () => ({
+  default: ({ type, menuType, nodeId, actionNodeIds, onImportSkills, onClose }: { type: string, menuType: string, nodeId?: string, actionNodeIds?: string[], onImportSkills?: () => void, onClose?: () => void }) => (
     <div
       data-testid={`node-menu-${menuType}`}
       data-type={type}
@@ -77,6 +94,11 @@ vi.mock('./node-menu', () => ({
           open-import-skill-modal
         </button>
       )}
+      {onClose && (
+        <button type="button" onClick={onClose}>
+          close-node-menu
+        </button>
+      )}
     </div>
   ),
 }))
@@ -196,6 +218,20 @@ describe('TreeContextMenu', () => {
       expect(screen.queryByTestId('import-skill-modal')).not.toBeInTheDocument()
     })
 
+    it('should wire the dynamic import loader and the menu close callback', async () => {
+      render(
+        <TreeContextMenu treeRef={{ current: { deselectAll: mocks.deselectAll } as never }}>
+          <div>blank area</div>
+        </TreeContextMenu>,
+      )
+
+      fireEvent.contextMenu(screen.getByText('blank area'))
+      fireEvent.click(screen.getByRole('button', { name: 'close-node-menu' }))
+
+      expect(mocks.dynamicImporters).toHaveLength(1)
+      await expect(mocks.dynamicImporters[0]()).resolves.toBeTruthy()
+    })
+
     it('should keep delete confirmation dialog mounted for item context actions', () => {
       mocks.fileOperations.showDeleteConfirm = true
 
@@ -212,5 +248,51 @@ describe('TreeContextMenu', () => {
       expect(screen.getByText('workflow.skillSidebar.menu.fileDeleteConfirmTitle')).toBeInTheDocument()
       expect(screen.getByText('workflow.skillSidebar.menu.fileDeleteConfirmContent')).toBeInTheDocument()
     })
+
+    it('should confirm folder deletion through the mounted dialog', () => {
+      mocks.fileOperations.showDeleteConfirm = true
+      mocks.getNode.mockReturnValue({
+        select: mocks.selectNode,
+        data: { name: 'docs' },
+      })
+
+      render(
+        <TreeContextMenu treeRef={{ current: { deselectAll: mocks.deselectAll, get: mocks.getNode } as never }}>
+          <div data-skill-tree-node-id="folder-1" data-skill-tree-node-type="folder" role="treeitem">
+            docs
+          </div>
+        </TreeContextMenu>,
+      )
+
+      fireEvent.contextMenu(screen.getByRole('treeitem'))
+      fireEvent.click(screen.getByRole('button', { name: /common\.operation\.confirm/i, hidden: true }))
+
+      expect(screen.getByText('workflow.skillSidebar.menu.deleteConfirmTitle')).toBeInTheDocument()
+      expect(screen.getByText('workflow.skillSidebar.menu.deleteConfirmContent')).toBeInTheDocument()
+      expect(mocks.fileOperations.handleDeleteConfirm).toHaveBeenCalledTimes(1)
+    })
+
+    it('should ignore context targets without a valid node id or menu type', () => {
+      render(
+        <TreeContextMenu treeRef={{ current: { deselectAll: mocks.deselectAll, get: mocks.getNode } as never }}>
+          <div>
+            <div data-skill-tree-node-id="" data-skill-tree-node-type="file" role="treeitem">
+              invalid-file
+            </div>
+            <div data-skill-tree-node-id="file-2" data-skill-tree-node-type="unknown" role="treeitem">
+              unknown-type
+            </div>
+          </div>
+        </TreeContextMenu>,
+      )
+
+      fireEvent.contextMenu(screen.getByText('invalid-file'))
+      fireEvent.contextMenu(screen.getByText('unknown-type'))
+
+      expect(mocks.getNode).not.toHaveBeenCalled()
+      expect(mocks.setSelectedNodeIds).not.toHaveBeenCalled()
+      expect(screen.getByTestId('node-menu-context')).toHaveAttribute('data-type', 'root')
+      expect(screen.getByTestId('node-menu-context')).toHaveAttribute('data-node-id', ROOT_ID)
+    })
   })
 })
diff --git a/web/app/components/workflow/skill/file-tree/tree/tree-edit-input.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-edit-input.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/file-tree/tree/tree-edit-input.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/tree-edit-input.spec.tsx
index 4953b634cef..adab06b6308 100644
--- a/web/app/components/workflow/skill/file-tree/tree/tree-edit-input.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-edit-input.spec.tsx
@@ -1,7 +1,7 @@
 import type { NodeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../type'
+import type { TreeNodeData } from '../../../type'
 import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import TreeEditInput from './tree-edit-input'
+import TreeEditInput from '.././tree-edit-input'
 
 type MockNodeApi = Pick<NodeApi<TreeNodeData>, 'data' | 'reset' | 'tree'>
 
diff --git a/web/app/components/workflow/skill/file-tree/tree/tree-guide-lines.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-guide-lines.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/file-tree/tree/tree-guide-lines.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/tree-guide-lines.spec.tsx
index 578c4ad7c51..2f79775818e 100644
--- a/web/app/components/workflow/skill/file-tree/tree/tree-guide-lines.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-guide-lines.spec.tsx
@@ -1,5 +1,5 @@
 import { render } from '@testing-library/react'
-import TreeGuideLines from './tree-guide-lines'
+import TreeGuideLines from '.././tree-guide-lines'
 
 describe('TreeGuideLines', () => {
   beforeEach(() => {
diff --git a/web/app/components/workflow/skill/file-tree/tree/tree-node-icon.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-node-icon.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/file-tree/tree/tree-node-icon.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/tree-node-icon.spec.tsx
index cb2296ca866..04d3001460c 100644
--- a/web/app/components/workflow/skill/file-tree/tree/tree-node-icon.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-node-icon.spec.tsx
@@ -1,11 +1,11 @@
 import { fireEvent, render, screen } from '@testing-library/react'
-import { TreeNodeIcon } from './tree-node-icon'
+import { TreeNodeIcon } from '.././tree-node-icon'
 
 const mocks = vi.hoisted(() => ({
   getFileIconType: vi.fn(() => 'document'),
 }))
 
-vi.mock('../../utils/file-utils', () => ({
+vi.mock('../../../utils/file-utils', () => ({
   getFileIconType: mocks.getFileIconType,
 }))
 
diff --git a/web/app/components/workflow/skill/file-tree/tree/tree-node.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-node.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/file-tree/tree/tree-node.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/tree-node.spec.tsx
index da29172ae19..75dbdc684bc 100644
--- a/web/app/components/workflow/skill/file-tree/tree/tree-node.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/tree-node.spec.tsx
@@ -1,7 +1,7 @@
 import type { NodeApi, NodeRendererProps, TreeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../type'
+import type { TreeNodeData } from '../../../type'
 import { fireEvent, render, screen } from '@testing-library/react'
-import TreeNode from './tree-node'
+import TreeNode from '.././tree-node'
 
 type MockWorkflowSelectorState = {
   dirtyContents: Set<string>
@@ -87,7 +87,7 @@ vi.mock('@/app/components/workflow/store', () => ({
   }),
 }))
 
-vi.mock('../../hooks/file-tree/interaction/use-tree-node-handlers', () => ({
+vi.mock('../../../hooks/file-tree/interaction/use-tree-node-handlers', () => ({
   useTreeNodeHandlers: () => ({
     handleClick: handlerMocks.handleClick,
     handleDoubleClick: handlerMocks.handleDoubleClick,
@@ -96,7 +96,7 @@ vi.mock('../../hooks/file-tree/interaction/use-tree-node-handlers', () => ({
   }),
 }))
 
-vi.mock('../../hooks/file-tree/dnd/use-folder-file-drop', () => ({
+vi.mock('../../../hooks/file-tree/dnd/use-folder-file-drop', () => ({
   useFolderFileDrop: () => ({
     isDragOver: dndMocks.isDragOver,
     isBlinking: dndMocks.isBlinking,
@@ -109,11 +109,11 @@ vi.mock('../../hooks/file-tree/dnd/use-folder-file-drop', () => ({
   }),
 }))
 
-vi.mock('../../hooks/file-tree/operations/use-file-operations', () => ({
+vi.mock('../../../hooks/file-tree/operations/use-file-operations', () => ({
   useFileOperations: () => fileOperationMocks,
 }))
 
-vi.mock('./node-menu', () => ({
+vi.mock('.././node-menu', () => ({
   default: ({
     type,
     menuType,
diff --git a/web/app/components/workflow/skill/file-tree/tree/upload-status-tooltip.spec.tsx b/web/app/components/workflow/skill/file-tree/tree/__tests__/upload-status-tooltip.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/file-tree/tree/upload-status-tooltip.spec.tsx
rename to web/app/components/workflow/skill/file-tree/tree/__tests__/upload-status-tooltip.spec.tsx
index efa9fe28a2c..a76371b6f7f 100644
--- a/web/app/components/workflow/skill/file-tree/tree/upload-status-tooltip.spec.tsx
+++ b/web/app/components/workflow/skill/file-tree/tree/__tests__/upload-status-tooltip.spec.tsx
@@ -1,5 +1,5 @@
 import { fireEvent, render, screen } from '@testing-library/react'
-import UploadStatusTooltip from './upload-status-tooltip'
+import UploadStatusTooltip from '.././upload-status-tooltip'
 
 type MockWorkflowState = {
   uploadStatus: 'idle' | 'uploading' | 'success' | 'partial_error'
diff --git a/web/app/components/workflow/skill/hooks/__tests__/use-fetch-text-content.spec.tsx b/web/app/components/workflow/skill/hooks/__tests__/use-fetch-text-content.spec.tsx
new file mode 100644
index 00000000000..947252e24b2
--- /dev/null
+++ b/web/app/components/workflow/skill/hooks/__tests__/use-fetch-text-content.spec.tsx
@@ -0,0 +1,56 @@
+import {
+  QueryClient,
+  QueryClientProvider,
+} from '@tanstack/react-query'
+import { renderHook, waitFor } from '@testing-library/react'
+import { useFetchTextContent } from '../use-fetch-text-content'
+
+const fetchMock = vi.fn<typeof fetch>()
+
+describe('use-fetch-text-content', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    vi.stubGlobal('fetch', fetchMock)
+  })
+
+  const createWrapper = () => {
+    const queryClient = new QueryClient({
+      defaultOptions: {
+        queries: {
+          retry: false,
+        },
+      },
+    })
+
+    return ({ children }: { children: React.ReactNode }) => (
+      <QueryClientProvider client={queryClient}>
+        {children}
+      </QueryClientProvider>
+    )
+  }
+
+  it('should fetch and cache text content when a download url is provided', async () => {
+    fetchMock.mockResolvedValue({
+      text: vi.fn().mockResolvedValue('hello world'),
+    } as unknown as Response)
+
+    const { result } = renderHook(() => useFetchTextContent('https://example.com/file.txt'), {
+      wrapper: createWrapper(),
+    })
+
+    await waitFor(() => expect(result.current.data).toBe('hello world'))
+
+    expect(fetchMock).toHaveBeenCalledWith('https://example.com/file.txt')
+    expect(result.current.isLoading).toBe(false)
+  })
+
+  it('should stay idle when the download url is missing', () => {
+    const { result } = renderHook(() => useFetchTextContent(undefined), {
+      wrapper: createWrapper(),
+    })
+
+    expect(fetchMock).not.toHaveBeenCalled()
+    expect(result.current.fetchStatus).toBe('idle')
+    expect(result.current.data).toBeUndefined()
+  })
+})
diff --git a/web/app/components/workflow/skill/hooks/use-file-node-view-state.spec.tsx b/web/app/components/workflow/skill/hooks/__tests__/use-file-node-view-state.spec.tsx
similarity index 85%
rename from web/app/components/workflow/skill/hooks/use-file-node-view-state.spec.tsx
rename to web/app/components/workflow/skill/hooks/__tests__/use-file-node-view-state.spec.tsx
index 4be17f2008b..7a0682cc68c 100644
--- a/web/app/components/workflow/skill/hooks/use-file-node-view-state.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/__tests__/use-file-node-view-state.spec.tsx
@@ -1,5 +1,5 @@
 import { renderHook, waitFor } from '@testing-library/react'
-import { useFileNodeViewState } from './use-file-node-view-state'
+import { useFileNodeViewState as useFileNodeViewPhase } from '.././use-file-node-view-state'
 
 type HookProps = {
   fileTabId: string | null
@@ -21,7 +21,7 @@ const createProps = (overrides: Partial<HookProps> = {}): HookProps => ({
 describe('useFileNodeViewState', () => {
   describe('resolution lifecycle', () => {
     it('should return ready when there is no active file tab', () => {
-      const { result } = renderHook(() => useFileNodeViewState(createProps({
+      const { result } = renderHook(() => useFileNodeViewPhase(createProps({
         fileTabId: null,
       })))
 
@@ -29,14 +29,14 @@ describe('useFileNodeViewState', () => {
     })
 
     it('should return resolving during initial node resolution', () => {
-      const { result } = renderHook(() => useFileNodeViewState(createProps()))
+      const { result } = renderHook(() => useFileNodeViewPhase(createProps()))
 
       expect(result.current).toBe('resolving')
     })
 
     it('should return missing when query settles without a matching node', () => {
       const { result, rerender } = renderHook(
-        (props: HookProps) => useFileNodeViewState(props),
+        (props: HookProps) => useFileNodeViewPhase(props),
         { initialProps: createProps() },
       )
 
@@ -51,7 +51,7 @@ describe('useFileNodeViewState', () => {
 
     it('should stay missing during background refetch after missing is resolved', async () => {
       const { result, rerender } = renderHook(
-        (props: HookProps) => useFileNodeViewState(props),
+        (props: HookProps) => useFileNodeViewPhase(props),
         { initialProps: createProps() },
       )
 
@@ -76,7 +76,7 @@ describe('useFileNodeViewState', () => {
 
     it('should become ready once the target node appears', () => {
       const { result, rerender } = renderHook(
-        (props: HookProps) => useFileNodeViewState(props),
+        (props: HookProps) => useFileNodeViewPhase(props),
         { initialProps: createProps() },
       )
 
@@ -92,7 +92,7 @@ describe('useFileNodeViewState', () => {
 
     it('should reset to resolving when switching to another file tab', () => {
       const { result, rerender } = renderHook(
-        (props: HookProps) => useFileNodeViewState(props),
+        (props: HookProps) => useFileNodeViewPhase(props),
         { initialProps: createProps({
           isNodeMapLoading: false,
           isNodeMapFetching: false,
diff --git a/web/app/components/workflow/skill/hooks/__tests__/use-file-type-info.spec.tsx b/web/app/components/workflow/skill/hooks/__tests__/use-file-type-info.spec.tsx
new file mode 100644
index 00000000000..b1a38915c55
--- /dev/null
+++ b/web/app/components/workflow/skill/hooks/__tests__/use-file-type-info.spec.tsx
@@ -0,0 +1,63 @@
+import { renderHook } from '@testing-library/react'
+import { useFileTypeInfo } from '../use-file-type-info'
+
+describe('useFileTypeInfo', () => {
+  it('should return a non-previewable default state when the file node is missing', () => {
+    const { result } = renderHook(() => useFileTypeInfo(undefined))
+
+    expect(result.current).toEqual({
+      isMarkdown: false,
+      isCodeOrText: false,
+      isImage: false,
+      isVideo: false,
+      isPdf: false,
+      isSQLite: false,
+      isEditable: false,
+      isMediaFile: false,
+      isPreviewable: false,
+    })
+  })
+
+  it('should classify markdown and editable files from their file name', () => {
+    const { result } = renderHook(() => useFileTypeInfo({
+      name: 'README.md',
+    }))
+
+    expect(result.current.isMarkdown).toBe(true)
+    expect(result.current.isEditable).toBe(true)
+    expect(result.current.isCodeOrText).toBe(false)
+    expect(result.current.isPreviewable).toBe(true)
+  })
+
+  it('should use an explicit extension override when provided', () => {
+    const { result } = renderHook(() => useFileTypeInfo({
+      name: 'README',
+      extension: '.PDF',
+    }))
+
+    expect(result.current.isPdf).toBe(true)
+    expect(result.current.isPreviewable).toBe(true)
+    expect(result.current.isEditable).toBe(false)
+  })
+
+  it('should fall back to the file name when the explicit extension is null', () => {
+    const { result } = renderHook(() => useFileTypeInfo({
+      name: 'clip.mp4',
+      extension: null,
+    }))
+
+    expect(result.current.isVideo).toBe(true)
+    expect(result.current.isMediaFile).toBe(true)
+    expect(result.current.isPreviewable).toBe(true)
+  })
+
+  it('should classify sqlite files as non-editable previews', () => {
+    const { result } = renderHook(() => useFileTypeInfo({
+      name: 'data.sqlite',
+    }))
+
+    expect(result.current.isSQLite).toBe(true)
+    expect(result.current.isEditable).toBe(false)
+    expect(result.current.isPreviewable).toBe(true)
+  })
+})
diff --git a/web/app/components/workflow/skill/hooks/use-skill-auto-save.spec.tsx b/web/app/components/workflow/skill/hooks/__tests__/use-skill-auto-save.spec.tsx
similarity index 94%
rename from web/app/components/workflow/skill/hooks/use-skill-auto-save.spec.tsx
rename to web/app/components/workflow/skill/hooks/__tests__/use-skill-auto-save.spec.tsx
index ea55cf47c05..e61ab0c7bca 100644
--- a/web/app/components/workflow/skill/hooks/use-skill-auto-save.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/__tests__/use-skill-auto-save.spec.tsx
@@ -1,11 +1,11 @@
 import { act, renderHook } from '@testing-library/react'
-import { useSkillAutoSave } from './use-skill-auto-save'
+import { useSkillAutoSave } from '.././use-skill-auto-save'
 
 const { mockSaveAllDirty } = vi.hoisted(() => ({
   mockSaveAllDirty: vi.fn(),
 }))
 
-vi.mock('./skill-save-context', () => ({
+vi.mock('.././skill-save-context', () => ({
   useSkillSaveManager: () => ({
     saveAllDirty: mockSaveAllDirty,
   }),
diff --git a/web/app/components/workflow/skill/hooks/use-skill-file-data.spec.tsx b/web/app/components/workflow/skill/hooks/__tests__/use-skill-file-data.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/hooks/use-skill-file-data.spec.tsx
rename to web/app/components/workflow/skill/hooks/__tests__/use-skill-file-data.spec.tsx
index 6e91f455183..186427ee68d 100644
--- a/web/app/components/workflow/skill/hooks/use-skill-file-data.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/__tests__/use-skill-file-data.spec.tsx
@@ -1,5 +1,5 @@
 import { renderHook } from '@testing-library/react'
-import { useSkillFileData } from './use-skill-file-data'
+import { useSkillFileData } from '.././use-skill-file-data'
 
 const { mockUseQuery, mockContentOptions, mockDownloadUrlOptions } = vi.hoisted(() => ({
   mockUseQuery: vi.fn(),
diff --git a/web/app/components/workflow/skill/hooks/use-skill-save-manager.spec.tsx b/web/app/components/workflow/skill/hooks/__tests__/use-skill-save-manager.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/hooks/use-skill-save-manager.spec.tsx
rename to web/app/components/workflow/skill/hooks/__tests__/use-skill-save-manager.spec.tsx
index adb1b7d9ecf..12133dea830 100644
--- a/web/app/components/workflow/skill/hooks/use-skill-save-manager.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/__tests__/use-skill-save-manager.spec.tsx
@@ -5,9 +5,9 @@ import { WorkflowContext } from '@/app/components/workflow/context'
 import { createWorkflowStore } from '@/app/components/workflow/store'
 import { useGlobalPublicStore } from '@/context/global-public-context'
 import { consoleQuery } from '@/service/client'
-import { START_TAB_ID } from '../constants'
-import { useSkillSaveManager } from './skill-save-context'
-import { SkillSaveProvider } from './use-skill-save-manager'
+import { START_TAB_ID } from '../../constants'
+import { useSkillSaveManager } from '.././skill-save-context'
+import { SkillSaveProvider } from '.././use-skill-save-manager'
 
 const {
   mockMutateAsync,
@@ -42,7 +42,7 @@ vi.mock('@/app/components/base/ui/toast', () => ({
   },
 }))
 
-vi.mock('../../collaboration/skills/skill-collaboration-manager', () => ({
+vi.mock('../../../collaboration/skills/skill-collaboration-manager', () => ({
   skillCollaborationManager: {
     isFileCollaborative: (fileId: string) => mockIsFileCollaborative(fileId),
     isLeader: (fileId: string) => mockIsLeader(fileId),
@@ -64,11 +64,11 @@ const createWrapper = (params: { appId: string, store: ReturnType<typeof createW
   const { appId, store, queryClient } = params
   return ({ children }: { children: ReactNode }) => (
     <QueryClientProvider client={queryClient}>
-      <WorkflowContext.Provider value={store}>
+      <WorkflowContext value={store}>
         <SkillSaveProvider appId={appId}>
           {children}
         </SkillSaveProvider>
-      </WorkflowContext.Provider>
+      </WorkflowContext>
     </QueryClientProvider>
   )
 }
diff --git a/web/app/components/workflow/skill/hooks/__tests__/use-sqlite-database.spec.tsx b/web/app/components/workflow/skill/hooks/__tests__/use-sqlite-database.spec.tsx
new file mode 100644
index 00000000000..222935d9175
--- /dev/null
+++ b/web/app/components/workflow/skill/hooks/__tests__/use-sqlite-database.spec.tsx
@@ -0,0 +1,330 @@
+import {
+  act,
+  renderHook,
+  waitFor,
+} from '@testing-library/react'
+
+const mocks = vi.hoisted(() => {
+  class MemoryVFS {
+    name = 'memory'
+    mapNameToFile = new Map<string, {
+      name: string
+      flags: number
+      size: number
+      data: ArrayBuffer
+    }>()
+
+    constructor() {
+      mocks.vfsInstances.push(this)
+    }
+  }
+
+  return {
+    fetch: vi.fn<typeof fetch>(),
+    sqliteFactory: vi.fn(),
+    sqliteESMFactory: vi.fn(async () => ({ wasm: true })),
+    execWithParams: vi.fn(),
+    openV2: vi.fn(),
+    close: vi.fn(),
+    vfsRegister: vi.fn(),
+    vfsInstances: [] as MemoryVFS[],
+    MemoryVFS,
+  }
+})
+
+vi.mock('wa-sqlite/dist/wa-sqlite.mjs', () => ({
+  default: () => mocks.sqliteESMFactory(),
+}))
+
+vi.mock('wa-sqlite', () => ({
+  Factory: () => ({
+    execWithParams: mocks.execWithParams,
+    open_v2: mocks.openV2,
+    close: mocks.close,
+    vfs_register: mocks.vfsRegister,
+  }),
+  SQLITE_OPEN_READONLY: 1,
+}))
+
+vi.mock('wa-sqlite/src/examples/MemoryVFS.js', () => ({
+  MemoryVFS: mocks.MemoryVFS,
+}))
+
+describe('useSQLiteDatabase', () => {
+  type HookProps = {
+    url: string | undefined
+  }
+
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.vfsInstances.length = 0
+    vi.stubGlobal('fetch', mocks.fetch)
+    vi.stubGlobal('crypto', {
+      randomUUID: () => 'uuid-1',
+    })
+
+    mocks.openV2.mockResolvedValue(99)
+    mocks.close.mockResolvedValue(undefined)
+    mocks.execWithParams.mockImplementation(async (_db: number, sql: string) => {
+      if (sql.includes('sqlite_master')) {
+        return {
+          columns: ['name'],
+          rows: [['users'], ['empty']],
+        }
+      }
+
+      if (sql === 'SELECT * FROM "users" LIMIT 5') {
+        return {
+          columns: ['id', 'name'],
+          rows: [[1, 'Ada']],
+        }
+      }
+
+      if (sql === 'SELECT * FROM "users" LIMIT 2') {
+        return {
+          columns: ['id', 'name'],
+          rows: [[1, 'Ada']],
+        }
+      }
+
+      if (sql === 'SELECT * FROM "empty"') {
+        return {
+          columns: [],
+          rows: [],
+        }
+      }
+
+      if (sql === 'PRAGMA table_info("empty")') {
+        return {
+          columns: ['cid', 'name'],
+          rows: [[0, 'id'], [1, 'name']],
+        }
+      }
+
+      return {
+        columns: ['id'],
+        rows: [],
+      }
+    })
+  })
+
+  const importHook = async () => {
+    vi.resetModules()
+    const hookModule = await import('../use-sqlite-database')
+    const constantsModule = await import('../sqlite/constants')
+    return {
+      useSQLiteDatabase: hookModule.useSQLiteDatabase,
+      TABLES_QUERY: constantsModule.TABLES_QUERY,
+    }
+  }
+
+  it('should load tables and query cached table data', async () => {
+    mocks.fetch.mockResolvedValue({
+      ok: true,
+      arrayBuffer: vi.fn().mockResolvedValue(new ArrayBuffer(8)),
+    } as unknown as Response)
+
+    const { useSQLiteDatabase, TABLES_QUERY } = await importHook()
+
+    const { result } = renderHook(() => useSQLiteDatabase('https://example.com/demo.db'))
+
+    await waitFor(() => expect(result.current.tables).toEqual(['users', 'empty']))
+    expect(mocks.fetch).toHaveBeenCalledWith('https://example.com/demo.db', { signal: expect.any(AbortSignal) })
+    expect(mocks.execWithParams).toHaveBeenCalledWith(99, TABLES_QUERY, [])
+
+    const first = await act(async () => result.current.queryTable('users', 5))
+    expect(first).toEqual({
+      columns: ['id', 'name'],
+      values: [[1, 'Ada']],
+    })
+
+    const second = await act(async () => result.current.queryTable('users', 5))
+    expect(second).toEqual(first)
+    expect(mocks.execWithParams).toHaveBeenCalledTimes(2)
+  })
+
+  it('should derive columns from pragma output when a table has no selected columns', async () => {
+    mocks.fetch.mockResolvedValue({
+      ok: true,
+      arrayBuffer: vi.fn().mockResolvedValue(new ArrayBuffer(8)),
+    } as unknown as Response)
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result } = renderHook(() => useSQLiteDatabase('https://example.com/demo.db'))
+
+    await waitFor(() => expect(result.current.tables).toContain('empty'))
+
+    const data = await act(async () => result.current.queryTable('empty'))
+
+    expect(data).toEqual({
+      columns: ['id', 'name'],
+      values: [],
+    })
+  })
+
+  it('should return null when querying an unknown table or before initialization', async () => {
+    mocks.fetch.mockResolvedValue({
+      ok: true,
+      arrayBuffer: vi.fn().mockResolvedValue(new ArrayBuffer(8)),
+    } as unknown as Response)
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result } = renderHook(() => useSQLiteDatabase('https://example.com/demo.db'))
+
+    expect(await act(async () => result.current.queryTable('users'))).toBeNull()
+
+    await waitFor(() => expect(result.current.tables).toEqual(['users', 'empty']))
+    expect(await act(async () => result.current.queryTable('missing'))).toBeNull()
+  })
+
+  it('should surface fetch errors and reset when the url is removed', async () => {
+    mocks.fetch
+      .mockResolvedValueOnce({
+        ok: false,
+        status: 500,
+        arrayBuffer: vi.fn(),
+      } as unknown as Response)
+      .mockResolvedValueOnce({
+        ok: true,
+        arrayBuffer: vi.fn().mockResolvedValue(new ArrayBuffer(8)),
+      } as unknown as Response)
+
+    const { useSQLiteDatabase } = await importHook()
+
+    const { result, rerender } = renderHook(
+      ({ url }: HookProps) => useSQLiteDatabase(url),
+      {
+        initialProps: {
+          url: 'https://example.com/broken.db',
+        } as HookProps,
+      },
+    )
+
+    await waitFor(() => expect(result.current.error?.message).toBe('Failed to fetch database: 500'))
+
+    rerender({ url: 'https://example.com/demo.db' } as HookProps)
+    await waitFor(() => expect(result.current.tables).toEqual(['users', 'empty']))
+
+    rerender({ url: undefined } as HookProps)
+    await waitFor(() => expect(result.current.tables).toEqual([]))
+    expect(mocks.close).toHaveBeenCalled()
+  })
+
+  it('should use a fallback temporary file name when crypto.randomUUID is unavailable', async () => {
+    vi.stubGlobal('crypto', undefined)
+    vi.spyOn(Date, 'now').mockReturnValue(1700000000000)
+    vi.spyOn(Math, 'random').mockReturnValue(0.5)
+    mocks.fetch.mockResolvedValue({
+      ok: true,
+      arrayBuffer: vi.fn().mockResolvedValue(new ArrayBuffer(8)),
+    } as unknown as Response)
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result } = renderHook(() => useSQLiteDatabase('https://example.com/fallback.db'))
+
+    await waitFor(() => expect(result.current.tables).toEqual(['users', 'empty']))
+    expect(mocks.openV2.mock.calls[0][0]).toMatch(/^preview-1700000000000-/)
+  })
+
+  it('should ignore a resolved fetch when the hook is cancelled before the response arrives', async () => {
+    let resolveFetch!: (value: Response) => void
+    const fetchPromise = new Promise<Response>((resolve) => {
+      resolveFetch = resolve
+    })
+    mocks.fetch.mockReturnValue(fetchPromise)
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result, rerender } = renderHook(
+      ({ url }: HookProps) => useSQLiteDatabase(url),
+      { initialProps: { url: 'https://example.com/cancel.db' } as HookProps },
+    )
+
+    rerender({ url: undefined } as HookProps)
+    resolveFetch({
+      ok: true,
+      arrayBuffer: vi.fn().mockResolvedValue(new ArrayBuffer(8)),
+    } as unknown as Response)
+
+    await waitFor(() => expect(result.current.tables).toEqual([]))
+    expect(mocks.openV2).not.toHaveBeenCalled()
+  })
+
+  it('should ignore an array buffer that resolves after cancellation', async () => {
+    let resolveArrayBuffer!: (value: ArrayBuffer) => void
+    const arrayBufferMock = vi.fn().mockImplementation(() => new Promise<ArrayBuffer>((resolve) => {
+      resolveArrayBuffer = resolve
+    }))
+    mocks.fetch.mockResolvedValue({
+      ok: true,
+      arrayBuffer: arrayBufferMock,
+    } as unknown as Response)
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result, rerender } = renderHook(
+      ({ url }: HookProps) => useSQLiteDatabase(url),
+      { initialProps: { url: 'https://example.com/cancel-buffer.db' } as HookProps },
+    )
+
+    await waitFor(() => expect(arrayBufferMock).toHaveBeenCalledTimes(1))
+    rerender({ url: undefined } as HookProps)
+    resolveArrayBuffer(new ArrayBuffer(8))
+
+    await waitFor(() => expect(result.current.tables).toEqual([]))
+    expect(mocks.openV2).not.toHaveBeenCalled()
+  })
+
+  it('should close a database opened after cancellation and remove its temp file', async () => {
+    let resolveOpen!: (value: number) => void
+    mocks.fetch.mockResolvedValue({
+      ok: true,
+      arrayBuffer: vi.fn().mockResolvedValue(new ArrayBuffer(8)),
+    } as unknown as Response)
+    mocks.openV2.mockImplementationOnce(() => new Promise<number>((resolve) => {
+      resolveOpen = resolve
+    }))
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result, rerender } = renderHook(
+      ({ url }: HookProps) => useSQLiteDatabase(url),
+      { initialProps: { url: 'https://example.com/cancel-open.db' } as HookProps },
+    )
+
+    await waitFor(() => expect(mocks.openV2).toHaveBeenCalledTimes(1))
+    rerender({ url: undefined } as HookProps)
+    resolveOpen(777)
+
+    await waitFor(() => expect(result.current.tables).toEqual([]))
+    expect(mocks.close).toHaveBeenCalledWith(777)
+    expect(mocks.vfsInstances.at(-1)?.mapNameToFile.size).toBe(0)
+  })
+
+  it('should wrap non-error failures when initialization rejects', async () => {
+    mocks.fetch.mockRejectedValue('network failure')
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result } = renderHook(() => useSQLiteDatabase('https://example.com/non-error.db'))
+
+    await waitFor(() => expect(result.current.error?.message).toBe('network failure'))
+    expect(result.current.error).toBeInstanceOf(Error)
+  })
+
+  it('should ignore rejected initialization after the hook has been cancelled', async () => {
+    let rejectFetch!: (reason?: unknown) => void
+    const fetchPromise = new Promise<Response>((_, reject) => {
+      rejectFetch = reject
+    })
+    mocks.fetch.mockReturnValue(fetchPromise)
+
+    const { useSQLiteDatabase } = await importHook()
+    const { result, rerender } = renderHook(
+      ({ url }: HookProps) => useSQLiteDatabase(url),
+      { initialProps: { url: 'https://example.com/cancel-error.db' } as HookProps },
+    )
+
+    rerender({ url: undefined } as HookProps)
+    rejectFetch(new Error('late failure'))
+
+    await waitFor(() => expect(result.current.tables).toEqual([]))
+    expect(result.current.error).toBeNull()
+  })
+})
diff --git a/web/app/components/workflow/skill/hooks/file-tree/data/use-skill-asset-tree.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/data/__tests__/use-skill-asset-tree.spec.tsx
similarity index 99%
rename from web/app/components/workflow/skill/hooks/file-tree/data/use-skill-asset-tree.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/data/__tests__/use-skill-asset-tree.spec.tsx
index 9f8d8db0f8a..1b28beb7f63 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/data/use-skill-asset-tree.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/data/__tests__/use-skill-asset-tree.spec.tsx
@@ -7,7 +7,7 @@ import {
   useExistingSkillNames,
   useSkillAssetNodeMap,
   useSkillAssetTreeData,
-} from './use-skill-asset-tree'
+} from '.././use-skill-asset-tree'
 
 const { mockUseQuery, mockAppAssetTreeOptions } = vi.hoisted(() => ({
   mockUseQuery: vi.fn(),
diff --git a/web/app/components/workflow/skill/hooks/file-tree/data/use-skill-tree-collaboration.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/data/__tests__/use-skill-tree-collaboration.spec.tsx
similarity index 99%
rename from web/app/components/workflow/skill/hooks/file-tree/data/use-skill-tree-collaboration.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/data/__tests__/use-skill-tree-collaboration.spec.tsx
index e5e4365e439..3523a7d4bb5 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/data/use-skill-tree-collaboration.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/data/__tests__/use-skill-tree-collaboration.spec.tsx
@@ -11,7 +11,7 @@ import { consoleQuery } from '@/service/client'
 import {
   useSkillTreeCollaboration,
   useSkillTreeUpdateEmitter,
-} from './use-skill-tree-collaboration'
+} from '.././use-skill-tree-collaboration'
 
 const {
   mockEmitTreeUpdate,
diff --git a/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-file-drop.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-file-drop.spec.tsx
index d90f8b6547e..4c0a8fb1faa 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-file-drop.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-file-drop.spec.tsx
@@ -176,6 +176,45 @@ describe('useFileDrop', () => {
       expect(store.getState().uploadStatus).toBe('idle')
     })
 
+    it('should ignore non-file items and null files from the drop payload', async () => {
+      const store = createWorkflowStore({})
+      const { result } = renderHook(() => useFileDrop(), { wrapper: createWrapper(store) })
+      const event = createDragEvent({
+        items: [
+          createDataTransferItem({ kind: 'string' }),
+          createDataTransferItem({ file: null }),
+        ],
+      })
+
+      await act(async () => {
+        await result.current.handleDrop(event as unknown as React.DragEvent, 'folder-null')
+      })
+
+      expect(mockPrepareSkillUploadFile).not.toHaveBeenCalled()
+      expect(mockUploadMutateAsync).not.toHaveBeenCalled()
+      expect(mockToastError).not.toHaveBeenCalled()
+    })
+
+    it('should handle drag payloads with missing item collections', async () => {
+      const store = createWorkflowStore({})
+      const { result } = renderHook(() => useFileDrop(), { wrapper: createWrapper(store) })
+      const event = {
+        preventDefault: vi.fn(),
+        stopPropagation: vi.fn(),
+        dataTransfer: {
+          types: ['Files'],
+          dropEffect: 'none',
+        },
+      } as unknown as React.DragEvent
+
+      await act(async () => {
+        await result.current.handleDrop(event, null)
+      })
+
+      expect(mockPrepareSkillUploadFile).not.toHaveBeenCalled()
+      expect(mockUploadMutateAsync).not.toHaveBeenCalled()
+    })
+
     it('should upload valid files while rejecting directories in a mixed drop payload', async () => {
       const store = createWorkflowStore({})
       const { result } = renderHook(() => useFileDrop(), { wrapper: createWrapper(store) })
diff --git a/web/app/components/workflow/skill/hooks/file-tree/dnd/use-folder-file-drop.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-folder-file-drop.spec.tsx
similarity index 74%
rename from web/app/components/workflow/skill/hooks/file-tree/dnd/use-folder-file-drop.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-folder-file-drop.spec.tsx
index 263f2899243..aec179b52bb 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/dnd/use-folder-file-drop.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-folder-file-drop.spec.tsx
@@ -1,12 +1,12 @@
 import type { ReactNode } from 'react'
 import type { NodeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import type { AppAssetTreeView } from '@/types/app-asset'
 import { act, renderHook } from '@testing-library/react'
 import { WorkflowContext } from '@/app/components/workflow/context'
 import { createWorkflowStore } from '@/app/components/workflow/store'
-import { INTERNAL_NODE_DRAG_TYPE } from '../../../constants'
-import { useFolderFileDrop } from './use-folder-file-drop'
+import { INTERNAL_NODE_DRAG_TYPE } from '../../../../constants'
+import { useFolderFileDrop } from '.././use-folder-file-drop'
 
 const {
   mockHandleDragOver,
@@ -16,7 +16,7 @@ const {
   mockHandleDrop: vi.fn(),
 }))
 
-vi.mock('./use-unified-drag', () => ({
+vi.mock('.././use-unified-drag', () => ({
   useUnifiedDrag: () => ({
     handleDragOver: mockHandleDragOver,
     handleDrop: mockHandleDrop,
@@ -25,17 +25,21 @@ vi.mock('./use-unified-drag', () => ({
 
 const createWrapper = (store: ReturnType<typeof createWorkflowStore>) => {
   return ({ children }: { children: ReactNode }) => (
-    <WorkflowContext.Provider value={store}>
+    <WorkflowContext value={store}>
       {children}
-    </WorkflowContext.Provider>
+    </WorkflowContext>
   )
 }
 
+type MutableNodeApi = NodeApi<TreeNodeData> & {
+  isOpen: boolean
+}
+
 const createNode = (params: {
   id?: string
   nodeType: 'file' | 'folder'
   isOpen?: boolean
-}): NodeApi<TreeNodeData> => {
+}): MutableNodeApi => {
   const node = {
     data: {
       id: params.id ?? 'node-1',
@@ -50,7 +54,7 @@ const createNode = (params: {
     open: vi.fn(),
   }
 
-  return node as unknown as NodeApi<TreeNodeData>
+  return node as unknown as MutableNodeApi
 }
 
 const createDragEvent = (types: string[]): React.DragEvent => {
@@ -112,6 +116,27 @@ describe('useFolderFileDrop', () => {
 
   // Scenario: drag handlers delegate only for supported drag events on folder nodes.
   describe('drag handlers', () => {
+    it('should track supported drag enter and leave events for folder nodes', () => {
+      const store = createWorkflowStore({})
+      const node = createNode({ id: 'folder-enter', nodeType: 'folder' })
+
+      const { result } = renderHook(() => useFolderFileDrop({
+        node,
+        treeChildren: EMPTY_TREE_CHILDREN,
+      }), {
+        wrapper: createWrapper(store),
+      })
+
+      const event = createDragEvent(['Files'])
+      act(() => {
+        result.current.dragHandlers.onDragEnter(event)
+        result.current.dragHandlers.onDragLeave(event)
+      })
+
+      expect(mockHandleDragOver).not.toHaveBeenCalled()
+      expect(mockHandleDrop).not.toHaveBeenCalled()
+    })
+
     it('should delegate drag over and drop for supported file drag events', () => {
       const store = createWorkflowStore({})
       const node = createNode({ id: 'folder-2', nodeType: 'folder' })
@@ -181,6 +206,24 @@ describe('useFolderFileDrop', () => {
         isFolder: true,
       })
     })
+
+    it('should ignore drop events on non-folder nodes', () => {
+      const store = createWorkflowStore({})
+      const node = createNode({ id: 'file-2', nodeType: 'file' })
+
+      const { result } = renderHook(() => useFolderFileDrop({
+        node,
+        treeChildren: EMPTY_TREE_CHILDREN,
+      }), {
+        wrapper: createWrapper(store),
+      })
+
+      act(() => {
+        result.current.dragHandlers.onDrop(createDragEvent(['Files']))
+      })
+
+      expect(mockHandleDrop).not.toHaveBeenCalled()
+    })
   })
 
   // Scenario: auto-expand lifecycle should blink first, expand later, and cleanup when drag state changes.
@@ -238,5 +281,31 @@ describe('useFolderFileDrop', () => {
       })
       expect(node.open).not.toHaveBeenCalled()
     })
+
+    it('should skip opening the folder when it becomes open before the expand timer fires', () => {
+      const store = createWorkflowStore({})
+      store.getState().setDragOverFolderId('folder-7')
+      const node = createNode({ id: 'folder-7', nodeType: 'folder', isOpen: false })
+
+      const { result } = renderHook(() => useFolderFileDrop({
+        node,
+        treeChildren: EMPTY_TREE_CHILDREN,
+      }), {
+        wrapper: createWrapper(store),
+      })
+
+      act(() => {
+        vi.advanceTimersByTime(1000)
+      })
+      expect(result.current.isBlinking).toBe(true)
+
+      node.isOpen = true
+      act(() => {
+        vi.advanceTimersByTime(1000)
+      })
+
+      expect(result.current.isBlinking).toBe(false)
+      expect(node.open).not.toHaveBeenCalled()
+    })
   })
 })
diff --git a/web/app/components/workflow/skill/hooks/file-tree/dnd/use-root-file-drop.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-root-file-drop.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/hooks/file-tree/dnd/use-root-file-drop.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-root-file-drop.spec.tsx
index b4356f30642..afa574ca2d0 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/dnd/use-root-file-drop.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-root-file-drop.spec.tsx
@@ -5,8 +5,8 @@ import { act, renderHook } from '@testing-library/react'
 import { useStore as useAppStore } from '@/app/components/app/store'
 import { WorkflowContext } from '@/app/components/workflow/context'
 import { createWorkflowStore } from '@/app/components/workflow/store'
-import { INTERNAL_NODE_DRAG_TYPE, ROOT_ID } from '../../../constants'
-import { useRootFileDrop } from './use-root-file-drop'
+import { INTERNAL_NODE_DRAG_TYPE, ROOT_ID } from '../../../../constants'
+import { useRootFileDrop } from '.././use-root-file-drop'
 
 const { mockUploadMutateAsync, uploadHookState } = vi.hoisted(() => ({
   mockUploadMutateAsync: vi.fn(),
@@ -39,9 +39,9 @@ const createDragEvent = ({ types, items = [] }: DragEventOptions): React.DragEve
 
 const createWrapper = (store: ReturnType<typeof createWorkflowStore>) => {
   return ({ children }: { children: ReactNode }) => (
-    <WorkflowContext.Provider value={store}>
+    <WorkflowContext value={store}>
       {children}
-    </WorkflowContext.Provider>
+    </WorkflowContext>
   )
 }
 
diff --git a/web/app/components/workflow/skill/hooks/file-tree/dnd/use-unified-drag.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-unified-drag.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/hooks/file-tree/dnd/use-unified-drag.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-unified-drag.spec.tsx
index fc84285cb0d..eecc5b6e4f7 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/dnd/use-unified-drag.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/dnd/__tests__/use-unified-drag.spec.tsx
@@ -4,8 +4,8 @@ import { act, renderHook } from '@testing-library/react'
 import { useStore as useAppStore } from '@/app/components/app/store'
 import { WorkflowContext } from '@/app/components/workflow/context'
 import { createWorkflowStore } from '@/app/components/workflow/store'
-import { INTERNAL_NODE_DRAG_TYPE } from '../../../constants'
-import { useUnifiedDrag } from './use-unified-drag'
+import { INTERNAL_NODE_DRAG_TYPE } from '../../../../constants'
+import { useUnifiedDrag } from '.././use-unified-drag'
 
 const { mockUploadMutateAsync, uploadHookState } = vi.hoisted(() => ({
   mockUploadMutateAsync: vi.fn(),
@@ -38,9 +38,9 @@ const createDragEvent = ({ types, items = [] }: DragEventOptions): React.DragEve
 
 const createWrapper = (store: ReturnType<typeof createWorkflowStore>) => {
   return ({ children }: { children: ReactNode }) => (
-    <WorkflowContext.Provider value={store}>
+    <WorkflowContext value={store}>
       {children}
-    </WorkflowContext.Provider>
+    </WorkflowContext>
   )
 }
 
diff --git a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-delayed-click.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-delayed-click.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/hooks/file-tree/interaction/use-delayed-click.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-delayed-click.spec.tsx
index f92ac175632..a40a55af760 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-delayed-click.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-delayed-click.spec.tsx
@@ -1,5 +1,5 @@
 import { act, renderHook } from '@testing-library/react'
-import { useDelayedClick } from './use-delayed-click'
+import { useDelayedClick } from '.././use-delayed-click'
 
 describe('useDelayedClick', () => {
   beforeEach(() => {
diff --git a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-inline-create-node.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-inline-create-node.spec.tsx
similarity index 95%
rename from web/app/components/workflow/skill/hooks/file-tree/interaction/use-inline-create-node.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-inline-create-node.spec.tsx
index c10a40cd8d3..9dc7336e1aa 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-inline-create-node.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-inline-create-node.spec.tsx
@@ -1,13 +1,13 @@
 import type { ReactNode } from 'react'
 import type { TreeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import type { App, AppSSO } from '@/types/app'
 import { act, renderHook } from '@testing-library/react'
 import { useStore as useAppStore } from '@/app/components/app/store'
 import { WorkflowContext } from '@/app/components/workflow/context'
 import { createWorkflowStore } from '@/app/components/workflow/store'
-import { START_TAB_ID } from '../../../constants'
-import { useInlineCreateNode } from './use-inline-create-node'
+import { START_TAB_ID } from '../../../../constants'
+import { useInlineCreateNode } from '.././use-inline-create-node'
 
 const {
   mockUploadMutate,
@@ -37,7 +37,7 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../data/use-skill-tree-collaboration', () => ({
+vi.mock('../../data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mockEmitTreeUpdate,
 }))
 
diff --git a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-skill-shortcuts.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-skill-shortcuts.spec.tsx
similarity index 80%
rename from web/app/components/workflow/skill/hooks/file-tree/interaction/use-skill-shortcuts.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-skill-shortcuts.spec.tsx
index d596a979f06..411b097dd6b 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-skill-shortcuts.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-skill-shortcuts.spec.tsx
@@ -1,9 +1,9 @@
 import type { RefObject } from 'react'
 import type { TreeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import { act, renderHook } from '@testing-library/react'
 import { getKeyboardKeyCodeBySystem } from '@/app/components/workflow/utils/common'
-import { useSkillShortcuts } from './use-skill-shortcuts'
+import { useSkillShortcuts } from '.././use-skill-shortcuts'
 
 const {
   mockUseKeyPress,
@@ -91,6 +91,25 @@ describe('useSkillShortcuts', () => {
       expect(mockCutNodes).toHaveBeenCalledWith(['file-1', 'file-2'])
     })
 
+    it('should ignore cut shortcut when the tree ref is missing even inside the tree container', () => {
+      const treeRef = { current: null }
+      renderHook(() => useSkillShortcuts({ treeRef }))
+
+      const container = document.createElement('div')
+      container.setAttribute('data-skill-tree-container', '')
+      const target = document.createElement('button')
+      container.appendChild(target)
+      const event = createShortcutEvent(target)
+
+      const cutShortcut = `${getKeyboardKeyCodeBySystem('ctrl')}.x`
+      act(() => {
+        registeredShortcutHandlers[cutShortcut](event)
+      })
+
+      expect(event.preventDefault).not.toHaveBeenCalled()
+      expect(mockCutNodes).not.toHaveBeenCalled()
+    })
+
     it('should cut selected nodes even when event target is outside tree container', () => {
       const treeRef = createTreeRef(['file-3'])
       renderHook(() => useSkillShortcuts({ treeRef }))
@@ -123,6 +142,25 @@ describe('useSkillShortcuts', () => {
       expect(mockCutNodes).not.toHaveBeenCalled()
     })
 
+    it('should ignore cut shortcut when there is no selection inside the tree container', () => {
+      const treeRef = createTreeRef([])
+      renderHook(() => useSkillShortcuts({ treeRef }))
+
+      const container = document.createElement('div')
+      container.setAttribute('data-skill-tree-container', '')
+      const target = document.createElement('button')
+      container.appendChild(target)
+      const event = createShortcutEvent(target)
+
+      const cutShortcut = `${getKeyboardKeyCodeBySystem('ctrl')}.x`
+      act(() => {
+        registeredShortcutHandlers[cutShortcut](event)
+      })
+
+      expect(event.preventDefault).not.toHaveBeenCalled()
+      expect(mockCutNodes).not.toHaveBeenCalled()
+    })
+
     it('should ignore cut shortcut when shortcuts are disabled', () => {
       const treeRef = createTreeRef(['file-1'])
       const { rerender } = renderHook(
diff --git a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-sync-tree-with-active-tab.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-sync-tree-with-active-tab.spec.tsx
similarity index 59%
rename from web/app/components/workflow/skill/hooks/file-tree/interaction/use-sync-tree-with-active-tab.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-sync-tree-with-active-tab.spec.tsx
index 05a5c722587..5eb7515e668 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-sync-tree-with-active-tab.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-sync-tree-with-active-tab.spec.tsx
@@ -1,11 +1,11 @@
 import type { ReactNode, RefObject } from 'react'
 import type { TreeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import { renderHook } from '@testing-library/react'
 import { WorkflowContext } from '@/app/components/workflow/context'
 import { createWorkflowStore } from '@/app/components/workflow/store'
-import { START_TAB_ID } from '../../../constants'
-import { useSyncTreeWithActiveTab } from './use-sync-tree-with-active-tab'
+import { START_TAB_ID } from '../../../../constants'
+import { useSyncTreeWithActiveTab } from '.././use-sync-tree-with-active-tab'
 
 type MockTreeNode = {
   id: string
@@ -18,9 +18,9 @@ type MockTreeNode = {
 
 const createWrapper = (store: ReturnType<typeof createWorkflowStore>) => {
   return ({ children }: { children: ReactNode }) => (
-    <WorkflowContext.Provider value={store}>
+    <WorkflowContext value={store}>
       {children}
-    </WorkflowContext.Provider>
+    </WorkflowContext>
   )
 }
 
@@ -38,6 +38,46 @@ describe('useSyncTreeWithActiveTab', () => {
     vi.spyOn(window, 'cancelAnimationFrame').mockImplementation(() => undefined)
   })
 
+  it('should skip syncing when there is no active tab', () => {
+    const store = createWorkflowStore({})
+    const requestAnimationFrameSpy = vi.spyOn(window, 'requestAnimationFrame')
+    const treeRef = createTreeRef({
+      selectedNodes: [],
+      deselectAll: vi.fn(),
+      get: vi.fn(),
+      openParents: vi.fn(),
+      select: vi.fn(),
+    })
+
+    renderHook(() => useSyncTreeWithActiveTab({
+      treeRef,
+      activeTabId: null,
+      isTreeLoading: false,
+    }), { wrapper: createWrapper(store) })
+
+    expect(requestAnimationFrameSpy).not.toHaveBeenCalled()
+  })
+
+  it('should skip syncing while the tree is still loading', () => {
+    const store = createWorkflowStore({})
+    const requestAnimationFrameSpy = vi.spyOn(window, 'requestAnimationFrame')
+    const treeRef = createTreeRef({
+      selectedNodes: [],
+      deselectAll: vi.fn(),
+      get: vi.fn(),
+      openParents: vi.fn(),
+      select: vi.fn(),
+    })
+
+    renderHook(() => useSyncTreeWithActiveTab({
+      treeRef,
+      activeTabId: 'file-1',
+      isTreeLoading: true,
+    }), { wrapper: createWrapper(store) })
+
+    expect(requestAnimationFrameSpy).not.toHaveBeenCalled()
+  })
+
   it('should clear tree selection when active tab is start tab', () => {
     const store = createWorkflowStore({})
     const deselectAll = vi.fn()
@@ -59,6 +99,38 @@ describe('useSyncTreeWithActiveTab', () => {
     expect(deselectAll).toHaveBeenCalledTimes(1)
   })
 
+  it('should leave selection untouched for artifact tabs when nothing is selected', () => {
+    const store = createWorkflowStore({})
+    const deselectAll = vi.fn()
+    const treeRef = createTreeRef({
+      selectedNodes: [],
+      deselectAll,
+      get: vi.fn(),
+      openParents: vi.fn(),
+      select: vi.fn(),
+    })
+
+    renderHook(() => useSyncTreeWithActiveTab({
+      treeRef,
+      activeTabId: 'artifact:file.png',
+      isTreeLoading: false,
+    }), { wrapper: createWrapper(store) })
+
+    expect(deselectAll).not.toHaveBeenCalled()
+  })
+
+  it('should stop when the tree ref is not attached yet', () => {
+    const store = createWorkflowStore({})
+
+    renderHook(() => useSyncTreeWithActiveTab({
+      treeRef: { current: null },
+      activeTabId: 'file-1',
+      isTreeLoading: false,
+    }), { wrapper: createWrapper(store) })
+
+    expect(store.getState().expandedFolderIds.size).toBe(0)
+  })
+
   it('should reveal ancestors and select active file node when node exists', () => {
     const store = createWorkflowStore({})
     const openParents = vi.fn()
@@ -127,6 +199,39 @@ describe('useSyncTreeWithActiveTab', () => {
     expect(select).not.toHaveBeenCalled()
   })
 
+  it('should avoid reopening parents when every ancestor is already open', () => {
+    const store = createWorkflowStore({})
+    const openParents = vi.fn()
+    const select = vi.fn()
+
+    const root: MockTreeNode = { id: 'root', isRoot: true, parent: null }
+    const folder: MockTreeNode = { id: 'folder-a', isRoot: false, parent: root, isOpen: true }
+    const fileNode: MockTreeNode = {
+      id: 'file-1',
+      isRoot: false,
+      parent: folder,
+      isSelected: false,
+      isFocused: false,
+    }
+
+    const treeRef = createTreeRef({
+      selectedNodes: [],
+      deselectAll: vi.fn(),
+      get: vi.fn(() => fileNode),
+      openParents,
+      select,
+    })
+
+    renderHook(() => useSyncTreeWithActiveTab({
+      treeRef,
+      activeTabId: 'file-1',
+      isTreeLoading: false,
+    }), { wrapper: createWrapper(store) })
+
+    expect(openParents).not.toHaveBeenCalled()
+    expect(select).toHaveBeenCalledWith('file-1')
+  })
+
   it('should retry syncing on syncSignal change when node appears later', () => {
     const store = createWorkflowStore({})
     const select = vi.fn()
diff --git a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-tree-node-handlers.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-tree-node-handlers.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/hooks/file-tree/interaction/use-tree-node-handlers.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-tree-node-handlers.spec.tsx
index 5878c090a27..b2f57899ee3 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/interaction/use-tree-node-handlers.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/interaction/__tests__/use-tree-node-handlers.spec.tsx
@@ -1,7 +1,7 @@
 import type { NodeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import { act, renderHook } from '@testing-library/react'
-import { useTreeNodeHandlers } from './use-tree-node-handlers'
+import { useTreeNodeHandlers } from '.././use-tree-node-handlers'
 
 const {
   mockClearArtifactSelection,
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-create-operations.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-create-operations.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/hooks/file-tree/operations/use-create-operations.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-create-operations.spec.tsx
index 33a1b9153f9..4d91d873e69 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-create-operations.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-create-operations.spec.tsx
@@ -2,7 +2,7 @@ import type { StoreApi } from 'zustand'
 import type { SkillEditorSliceShape, UploadStatus } from '@/app/components/workflow/store/workflow/skill-editor/types'
 import type { AppAssetNode, BatchUploadNodeInput } from '@/types/app-asset'
 import { act, renderHook } from '@testing-library/react'
-import { useCreateOperations } from './use-create-operations'
+import { useCreateOperations } from '.././use-create-operations'
 
 type UploadMutationPayload = {
   appId: string
@@ -48,11 +48,11 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../../../utils/skill-upload-utils', () => ({
+vi.mock('../../../../utils/skill-upload-utils', () => ({
   prepareSkillUploadFile: mocks.prepareSkillUploadFile,
 }))
 
-vi.mock('../data/use-skill-tree-collaboration', () => ({
+vi.mock('../../data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mocks.emitTreeUpdate,
 }))
 
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-download-operation.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-download-operation.spec.tsx
similarity index 89%
rename from web/app/components/workflow/skill/hooks/file-tree/operations/use-download-operation.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-download-operation.spec.tsx
index 7a12e131f49..780432c92b9 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-download-operation.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-download-operation.spec.tsx
@@ -1,5 +1,5 @@
 import { act, renderHook, waitFor } from '@testing-library/react'
-import { useDownloadOperation } from './use-download-operation'
+import { useDownloadOperation } from '.././use-download-operation'
 
 type DownloadRequest = {
   params: {
@@ -130,6 +130,25 @@ describe('useDownloadOperation', () => {
       expect(result.current.isDownloading).toBe(false)
     })
 
+    it('should preserve raw content when parsed text payload has no content field', async () => {
+      mockGetFileContent.mockResolvedValueOnce({ content: '{"title":"Skill"}' })
+      const onClose = vi.fn()
+      const { result } = renderHook(() => useDownloadOperation({
+        appId: 'app-1',
+        nodeId: 'node-raw',
+        fileName: 'config.json',
+        onClose,
+      }))
+
+      await act(async () => {
+        await result.current.handleDownload()
+      })
+
+      const downloadedBlob = mockDownloadBlob.mock.calls.at(-1)?.[0].data
+      await expect(downloadedBlob?.text()).resolves.toBe('{"title":"Skill"}')
+      expect(mockDownloadUrl).not.toHaveBeenCalled()
+    })
+
     it('should download binary file from download url when file is not text', async () => {
       const onClose = vi.fn()
       const { result } = renderHook(() => useDownloadOperation({
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-file-operations.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-file-operations.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/hooks/file-tree/operations/use-file-operations.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-file-operations.spec.tsx
index 3bbebc26bca..2d9b32d1fe6 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-file-operations.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-file-operations.spec.tsx
@@ -1,11 +1,11 @@
 import type { RefObject } from 'react'
 import type { NodeApi, TreeApi } from 'react-arborist'
 import type { StoreApi } from 'zustand'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import type { SkillEditorSliceShape } from '@/app/components/workflow/store/workflow/skill-editor/types'
 import type { AppAssetTreeResponse } from '@/types/app-asset'
 import { renderHook } from '@testing-library/react'
-import { useFileOperations } from './use-file-operations'
+import { useFileOperations } from '.././use-file-operations'
 
 type AppStoreState = {
   appDetail?: {
@@ -127,17 +127,17 @@ vi.mock('@/app/components/workflow/store', () => ({
   useWorkflowStore: () => mocks.workflowStore,
 }))
 
-vi.mock('../data/use-skill-asset-tree', () => ({
+vi.mock('../../data/use-skill-asset-tree', () => ({
   useSkillAssetTreeData: () => ({
     data: mocks.treeData,
   }),
 }))
 
-vi.mock('../../../utils/tree-utils', () => ({
+vi.mock('../../../../utils/tree-utils', () => ({
   toApiParentId: mocks.toApiParentId,
 }))
 
-vi.mock('./use-create-operations', () => ({
+vi.mock('.././use-create-operations', () => ({
   useCreateOperations: (options: {
     parentId: string | null
     appId: string
@@ -146,7 +146,7 @@ vi.mock('./use-create-operations', () => ({
   }) => mocks.createOpsHook(options),
 }))
 
-vi.mock('./use-modify-operations', () => ({
+vi.mock('.././use-modify-operations', () => ({
   useModifyOperations: (options: {
     nodeId: string
     node?: NodeApi<TreeNodeData>
@@ -158,7 +158,7 @@ vi.mock('./use-modify-operations', () => ({
   }) => mocks.modifyOpsHook(options),
 }))
 
-vi.mock('./use-download-operation', () => ({
+vi.mock('.././use-download-operation', () => ({
   useDownloadOperation: (options: {
     appId: string
     nodeId: string
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-modify-operations.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-modify-operations.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/hooks/file-tree/operations/use-modify-operations.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-modify-operations.spec.tsx
index d5afb4962b6..d05c24fb835 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-modify-operations.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-modify-operations.spec.tsx
@@ -1,11 +1,11 @@
 import type { RefObject } from 'react'
 import type { NodeApi, TreeApi } from 'react-arborist'
 import type { StoreApi } from 'zustand'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import type { SkillEditorSliceShape } from '@/app/components/workflow/store/workflow/skill-editor/types'
 import type { AppAssetTreeResponse } from '@/types/app-asset'
 import { act, renderHook } from '@testing-library/react'
-import { useModifyOperations } from './use-modify-operations'
+import { useModifyOperations } from '.././use-modify-operations'
 
 type DeleteMutationPayload = {
   appId: string
@@ -29,11 +29,11 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../data/use-skill-tree-collaboration', () => ({
+vi.mock('../../data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mocks.emitTreeUpdate,
 }))
 
-vi.mock('../../../utils/tree-utils', () => ({
+vi.mock('../../../../utils/tree-utils', () => ({
   getAllDescendantFileIds: mocks.getAllDescendantFileIds,
   isDescendantOf: mocks.isDescendantOf,
 }))
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-node-move.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-node-move.spec.tsx
similarity index 95%
rename from web/app/components/workflow/skill/hooks/file-tree/operations/use-node-move.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-node-move.spec.tsx
index a3f806c24b0..43eacb0b9cb 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-node-move.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-node-move.spec.tsx
@@ -1,5 +1,5 @@
 import { act, renderHook } from '@testing-library/react'
-import { useNodeMove } from './use-node-move'
+import { useNodeMove } from '.././use-node-move'
 
 type AppStoreState = {
   appDetail?: {
@@ -38,11 +38,11 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../data/use-skill-tree-collaboration', () => ({
+vi.mock('../../data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mocks.emitTreeUpdate,
 }))
 
-vi.mock('../../../utils/tree-utils', () => ({
+vi.mock('../../../../utils/tree-utils', () => ({
   toApiParentId: mocks.toApiParentId,
 }))
 
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-node-reorder.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-node-reorder.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/hooks/file-tree/operations/use-node-reorder.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-node-reorder.spec.tsx
index 378be4bb719..254f1e1faec 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-node-reorder.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-node-reorder.spec.tsx
@@ -1,5 +1,5 @@
 import { act, renderHook } from '@testing-library/react'
-import { useNodeReorder } from './use-node-reorder'
+import { useNodeReorder } from '.././use-node-reorder'
 
 type AppStoreState = {
   appDetail?: {
@@ -37,7 +37,7 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../data/use-skill-tree-collaboration', () => ({
+vi.mock('../../data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mocks.emitTreeUpdate,
 }))
 
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-paste-operation.spec.tsx b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-paste-operation.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/hooks/file-tree/operations/use-paste-operation.spec.tsx
rename to web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-paste-operation.spec.tsx
index a4c48b1269d..0230c4f4816 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-paste-operation.spec.tsx
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/__tests__/use-paste-operation.spec.tsx
@@ -1,9 +1,9 @@
 import type { RefObject } from 'react'
 import type { TreeApi } from 'react-arborist'
-import type { TreeNodeData } from '../../../type'
+import type { TreeNodeData } from '../../../../type'
 import type { AppAssetTreeResponse } from '@/types/app-asset'
 import { act, renderHook, waitFor } from '@testing-library/react'
-import { usePasteOperation } from './use-paste-operation'
+import { usePasteOperation } from '.././use-paste-operation'
 
 type MoveMutationPayload = {
   appId: string
@@ -83,11 +83,11 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../data/use-skill-tree-collaboration', () => ({
+vi.mock('../../data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mocks.emitTreeUpdate,
 }))
 
-vi.mock('../../../utils/tree-utils', () => ({
+vi.mock('../../../../utils/tree-utils', () => ({
   getTargetFolderIdFromSelection: mocks.getTargetFolderIdFromSelection,
   toApiParentId: mocks.toApiParentId,
   findNodeById: mocks.findNodeById,
diff --git a/web/app/components/workflow/skill/hooks/file-tree/operations/use-download-operation.ts b/web/app/components/workflow/skill/hooks/file-tree/operations/use-download-operation.ts
index 42ad5c9e043..7914233ce88 100644
--- a/web/app/components/workflow/skill/hooks/file-tree/operations/use-download-operation.ts
+++ b/web/app/components/workflow/skill/hooks/file-tree/operations/use-download-operation.ts
@@ -37,6 +37,7 @@ export function useDownloadOperation({
         const { content } = await consoleClient.appAsset.getFileContent({
           params: { appId, nodeId },
         })
+        const textFileName = fileName!
         let rawText = content
         try {
           const parsed = JSON.parse(content) as { content?: string }
@@ -48,7 +49,7 @@ export function useDownloadOperation({
 
         downloadBlob({
           data: new Blob([rawText], { type: 'text/plain;charset=utf-8' }),
-          fileName: fileName || 'download.txt',
+          fileName: textFileName,
         })
       }
       else {
diff --git a/web/app/components/workflow/skill/hooks/sqlite/__tests__/constants.spec.ts b/web/app/components/workflow/skill/hooks/sqlite/__tests__/constants.spec.ts
new file mode 100644
index 00000000000..d56f288243f
--- /dev/null
+++ b/web/app/components/workflow/skill/hooks/sqlite/__tests__/constants.spec.ts
@@ -0,0 +1,7 @@
+import { TABLES_QUERY } from '../constants'
+
+describe('sqlite constants', () => {
+  it('should expose the table listing query', () => {
+    expect(TABLES_QUERY).toBe('SELECT name FROM sqlite_master WHERE type=\'table\' AND name NOT LIKE \'sqlite_%\' ORDER BY name')
+  })
+})
diff --git a/web/app/components/workflow/skill/skill-body/sidebar-search-add.spec.tsx b/web/app/components/workflow/skill/skill-body/__tests__/sidebar-search-add.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/skill-body/sidebar-search-add.spec.tsx
rename to web/app/components/workflow/skill/skill-body/__tests__/sidebar-search-add.spec.tsx
index 756592db012..486b700c90e 100644
--- a/web/app/components/workflow/skill/skill-body/sidebar-search-add.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/__tests__/sidebar-search-add.spec.tsx
@@ -1,7 +1,7 @@
 import type { AppAssetTreeResponse, AppAssetTreeView } from '@/types/app-asset'
 import { fireEvent, render, screen } from '@testing-library/react'
-import { ROOT_ID } from '../constants'
-import SidebarSearchAdd from './sidebar-search-add'
+import { ROOT_ID } from '../../constants'
+import SidebarSearchAdd from '.././sidebar-search-add'
 
 type WorkflowStoreState = {
   fileTreeSearchTerm: string
@@ -59,7 +59,9 @@ const mocks = vi.hoisted(() => ({
 }))
 
 vi.mock('next/dynamic', () => ({
-  default: () => {
+  default: (loader: () => Promise<unknown>) => {
+    void loader()
+
     const MockImportSkillModal = ({ isOpen, onClose }: { isOpen: boolean, onClose: () => void }) => {
       if (!isOpen)
         return null
@@ -86,11 +88,11 @@ vi.mock('@/app/components/workflow/store', () => ({
   }),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useSkillAssetTreeData: () => ({ data: mocks.treeData }),
 }))
 
-vi.mock('../hooks/file-tree/operations/use-file-operations', () => ({
+vi.mock('../../hooks/file-tree/operations/use-file-operations', () => ({
   useFileOperations: (options: unknown) => {
     mocks.useFileOperations(options)
     return mocks.fileOperations
diff --git a/web/app/components/workflow/skill/skill-body/layout/content-area.spec.tsx b/web/app/components/workflow/skill/skill-body/layout/__tests__/content-area.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/skill-body/layout/content-area.spec.tsx
rename to web/app/components/workflow/skill/skill-body/layout/__tests__/content-area.spec.tsx
index 655e75d610b..6dc743be5d2 100644
--- a/web/app/components/workflow/skill/skill-body/layout/content-area.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/layout/__tests__/content-area.spec.tsx
@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react'
-import ContentArea from './content-area'
+import ContentArea from '.././content-area'
 
 describe('ContentArea', () => {
   describe('Rendering', () => {
diff --git a/web/app/components/workflow/skill/skill-body/layout/content-body.spec.tsx b/web/app/components/workflow/skill/skill-body/layout/__tests__/content-body.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/skill-body/layout/content-body.spec.tsx
rename to web/app/components/workflow/skill/skill-body/layout/__tests__/content-body.spec.tsx
index 98519a48b4f..a0239784605 100644
--- a/web/app/components/workflow/skill/skill-body/layout/content-body.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/layout/__tests__/content-body.spec.tsx
@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react'
-import ContentBody from './content-body'
+import ContentBody from '.././content-body'
 
 describe('ContentBody', () => {
   describe('Rendering', () => {
diff --git a/web/app/components/workflow/skill/skill-body/layout/sidebar.spec.tsx b/web/app/components/workflow/skill/skill-body/layout/__tests__/sidebar.spec.tsx
similarity index 95%
rename from web/app/components/workflow/skill/skill-body/layout/sidebar.spec.tsx
rename to web/app/components/workflow/skill/skill-body/layout/__tests__/sidebar.spec.tsx
index 365520da789..e8a0325b84f 100644
--- a/web/app/components/workflow/skill/skill-body/layout/sidebar.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/layout/__tests__/sidebar.spec.tsx
@@ -1,7 +1,7 @@
 import { render, screen } from '@testing-library/react'
 import { STORAGE_KEYS } from '@/config/storage-keys'
-import { SIDEBAR_DEFAULT_WIDTH, SIDEBAR_MAX_WIDTH, SIDEBAR_MIN_WIDTH } from '../../constants'
-import Sidebar from './sidebar'
+import { SIDEBAR_DEFAULT_WIDTH, SIDEBAR_MAX_WIDTH, SIDEBAR_MIN_WIDTH } from '../../../constants'
+import Sidebar from '.././sidebar'
 
 type ResizePanelParams = {
   direction?: 'horizontal' | 'vertical' | 'both'
@@ -23,7 +23,7 @@ vi.mock('ahooks', () => ({
   }),
 }))
 
-vi.mock('../../../nodes/_base/hooks/use-resize-panel', () => ({
+vi.mock('../../../../nodes/_base/hooks/use-resize-panel', () => ({
   useResizePanel: (params?: ResizePanelParams) => {
     mocks.lastResizeParams = params
     return {
diff --git a/web/app/components/workflow/skill/skill-body/layout/skill-page-layout.spec.tsx b/web/app/components/workflow/skill/skill-body/layout/__tests__/skill-page-layout.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/skill-body/layout/skill-page-layout.spec.tsx
rename to web/app/components/workflow/skill/skill-body/layout/__tests__/skill-page-layout.spec.tsx
index 4c4504d7a27..1c6a4be6821 100644
--- a/web/app/components/workflow/skill/skill-body/layout/skill-page-layout.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/layout/__tests__/skill-page-layout.spec.tsx
@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react'
-import SkillPageLayout from './skill-page-layout'
+import SkillPageLayout from '.././skill-page-layout'
 
 describe('SkillPageLayout', () => {
   describe('Rendering', () => {
diff --git a/web/app/components/workflow/skill/skill-body/panels/artifact-content-panel.spec.tsx b/web/app/components/workflow/skill/skill-body/panels/__tests__/artifact-content-panel.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/skill-body/panels/artifact-content-panel.spec.tsx
rename to web/app/components/workflow/skill/skill-body/panels/__tests__/artifact-content-panel.spec.tsx
index d1c162b3387..bf4ceaa0fd8 100644
--- a/web/app/components/workflow/skill/skill-body/panels/artifact-content-panel.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/panels/__tests__/artifact-content-panel.spec.tsx
@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react'
-import ArtifactContentPanel from './artifact-content-panel'
+import ArtifactContentPanel from '.././artifact-content-panel'
 
 type WorkflowStoreState = {
   activeTabId: string | null
diff --git a/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/file-editor-renderer.spec.tsx b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/file-editor-renderer.spec.tsx
new file mode 100644
index 00000000000..b9c4bb7b43d
--- /dev/null
+++ b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/file-editor-renderer.spec.tsx
@@ -0,0 +1,157 @@
+import type { OnMount } from '@monaco-editor/react'
+import { act, render, screen } from '@testing-library/react'
+
+import FileEditorRenderer from '../file-editor-renderer'
+
+const mocks = vi.hoisted(() => ({
+  theme: 'light',
+  isClient: true,
+  loaderConfig: vi.fn(),
+  editorProps: [] as Array<Record<string, unknown>>,
+  markdownProps: [] as Array<Record<string, unknown>>,
+  monacoSetTheme: vi.fn(),
+  getFileLanguage: vi.fn((_: string) => 'typescript'),
+}))
+
+vi.mock('@monaco-editor/react', () => ({
+  loader: {
+    config: (config: unknown) => mocks.loaderConfig(config),
+  },
+}))
+
+vi.mock('@/hooks/use-theme', () => ({
+  default: () => ({ theme: mocks.theme }),
+}))
+
+vi.mock('@/types/app', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@/types/app')>()
+  return {
+    ...actual,
+    Theme: { ...actual.Theme, light: 'light', dark: 'dark' },
+  }
+})
+
+vi.mock('@/utils/client', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@/utils/client')>()
+  return {
+    ...actual,
+    get isClient() {
+      return mocks.isClient
+    },
+  }
+})
+
+vi.mock('../../../../utils/file-utils', () => ({
+  getFileLanguage: (name: string) => mocks.getFileLanguage(name),
+}))
+
+vi.mock('../../../../editor/code-file-editor', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.editorProps.push(props)
+    return (
+      <button
+        type="button"
+        onClick={() => (props.onMount as OnMount)({} as Parameters<OnMount>[0], { editor: { setTheme: mocks.monacoSetTheme } } as Parameters<OnMount>[1])}
+      >
+        mount-code-editor
+      </button>
+    )
+  },
+}))
+
+vi.mock('../../../../editor/markdown-file-editor', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.markdownProps.push(props)
+    return <div data-testid="markdown-editor">{String(props.value)}</div>
+  },
+}))
+
+describe('FileEditorRenderer', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.theme = 'light'
+    mocks.isClient = true
+    mocks.editorProps.length = 0
+    mocks.markdownProps.length = 0
+  })
+
+  it('should render the markdown editor with the collaborative props intact', () => {
+    render(
+      <FileEditorRenderer
+        state={{
+          kind: 'editor',
+          editor: 'markdown',
+          fileTabId: 'file-1',
+          fileName: 'SKILL.md',
+          content: '# Skill',
+          onChange: vi.fn(),
+          autoFocus: true,
+          onAutoFocus: vi.fn(),
+          collaborationEnabled: true,
+        }}
+      />,
+    )
+
+    expect(screen.getByTestId('markdown-editor')).toHaveTextContent('# Skill')
+    expect(mocks.markdownProps[0]).toMatchObject({
+      instanceId: 'file-1',
+      autoFocus: true,
+      collaborationEnabled: true,
+    })
+  })
+
+  it('should render the code editor with the default theme before Monaco mounts', () => {
+    render(
+      <FileEditorRenderer
+        state={{
+          kind: 'editor',
+          editor: 'code',
+          fileTabId: 'file-2',
+          fileName: 'main.ts',
+          content: 'const a = 1',
+          onChange: vi.fn(),
+          autoFocus: false,
+          onAutoFocus: vi.fn(),
+          collaborationEnabled: false,
+        }}
+      />,
+    )
+
+    expect(mocks.editorProps[0]).toMatchObject({
+      fileId: 'file-2',
+      theme: 'default-theme',
+      value: 'const a = 1',
+      collaborationEnabled: false,
+    })
+    expect(mocks.getFileLanguage).toHaveBeenCalledWith('main.ts')
+  })
+
+  it('should switch the code editor theme after Monaco mounts in dark mode', () => {
+    mocks.theme = 'dark'
+
+    render(
+      <FileEditorRenderer
+        state={{
+          kind: 'editor',
+          editor: 'code',
+          fileTabId: 'file-3',
+          fileName: 'main.ts',
+          content: 'const a = 1',
+          onChange: vi.fn(),
+          autoFocus: false,
+          onAutoFocus: vi.fn(),
+          collaborationEnabled: true,
+        }}
+      />,
+    )
+
+    act(() => {
+      screen.getByRole('button', { name: 'mount-code-editor' }).click()
+    })
+
+    expect(mocks.monacoSetTheme).toHaveBeenCalledWith('vs-dark')
+    expect(mocks.editorProps.at(-1)).toMatchObject({
+      theme: 'vs-dark',
+    })
+  })
+})
diff --git a/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/file-preview-renderer.spec.tsx b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/file-preview-renderer.spec.tsx
new file mode 100644
index 00000000000..4ca304324d8
--- /dev/null
+++ b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/file-preview-renderer.spec.tsx
@@ -0,0 +1,116 @@
+import { render, screen } from '@testing-library/react'
+import * as React from 'react'
+import Loading from '@/app/components/base/loading'
+import FilePreviewRenderer from '../file-preview-renderer'
+
+const mocks = vi.hoisted(() => ({
+  dynamicLoaders: [] as Array<() => React.ReactNode>,
+  dynamicImporters: [] as Array<() => Promise<unknown>>,
+  dynamicComponents: [
+    ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="sqlite-preview">{downloadUrl}</div>,
+    ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="pdf-preview">{downloadUrl}</div>,
+  ],
+  dynamicIndex: 0,
+}))
+
+vi.mock('@/next/dynamic', () => ({
+  default: (loader: () => Promise<unknown>, options?: { loading?: () => React.ReactNode }) => {
+    mocks.dynamicImporters.push(loader)
+    if (options?.loading)
+      mocks.dynamicLoaders.push(options.loading)
+    return mocks.dynamicComponents[mocks.dynamicIndex++]
+  },
+}))
+
+vi.mock('../../../../viewer/media-file-preview', () => ({
+  default: ({ type, src }: { type: string, src: string }) => <div data-testid="media-preview">{`${type}:${src}`}</div>,
+}))
+
+vi.mock('../../../../viewer/unsupported-file-download', () => ({
+  default: ({ name, size, downloadUrl }: { name: string, size?: number, downloadUrl: string }) => (
+    <div data-testid="unsupported-preview">{`${name}:${String(size)}:${downloadUrl}`}</div>
+  ),
+}))
+
+vi.mock('../../../../viewer/sqlite-file-preview', () => ({
+  default: ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="resolved-sqlite-preview">{downloadUrl}</div>,
+}))
+
+vi.mock('../../../../viewer/pdf-file-preview', () => ({
+  default: ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="resolved-pdf-preview">{downloadUrl}</div>,
+}))
+describe('FilePreviewRenderer', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.dynamicLoaders.length = 0
+    mocks.dynamicImporters.length = 0
+    mocks.dynamicIndex = 0
+  })
+
+  it('should render media, sqlite, pdf, and unsupported previews for each preview state', () => {
+    const { rerender } = render(
+      <FilePreviewRenderer
+        state={{ kind: 'preview', preview: 'media', mediaType: 'video', downloadUrl: 'https://example.com/demo.mp4' }}
+      />,
+    )
+
+    expect(screen.getByTestId('media-preview')).toHaveTextContent('video:https://example.com/demo.mp4')
+
+    rerender(
+      <FilePreviewRenderer
+        state={{ kind: 'preview', preview: 'sqlite', fileTabId: 'file-1', downloadUrl: 'https://example.com/demo.db' }}
+      />,
+    )
+    expect(screen.getByTestId('sqlite-preview')).toHaveTextContent('https://example.com/demo.db')
+
+    rerender(
+      <FilePreviewRenderer
+        state={{ kind: 'preview', preview: 'pdf', downloadUrl: 'https://example.com/demo.pdf' }}
+      />,
+    )
+    expect(screen.getByTestId('pdf-preview')).toHaveTextContent('https://example.com/demo.pdf')
+
+    rerender(
+      <FilePreviewRenderer
+        state={{
+          kind: 'preview',
+          preview: 'unsupported',
+          fileName: 'archive.bin',
+          fileSize: 42,
+          downloadUrl: 'https://example.com/archive.bin',
+        }}
+      />,
+    )
+    expect(screen.getByTestId('unsupported-preview')).toHaveTextContent('archive.bin:42:https://example.com/archive.bin')
+  })
+
+  it('should expose loading placeholders and dynamic importers for async previews', async () => {
+    vi.resetModules()
+    mocks.dynamicLoaders.length = 0
+    mocks.dynamicImporters.length = 0
+    mocks.dynamicIndex = 0
+
+    const previewRendererModule = await import('../file-preview-renderer')
+    const FreshFilePreviewRenderer = previewRendererModule.default
+
+    render(
+      <FreshFilePreviewRenderer
+        state={{ kind: 'preview', preview: 'sqlite', fileTabId: 'file-1', downloadUrl: 'https://example.com/demo.db' }}
+      />,
+    )
+
+    expect(mocks.dynamicLoaders).toHaveLength(2)
+    expect(mocks.dynamicImporters).toHaveLength(2)
+
+    for (const renderLoader of mocks.dynamicLoaders) {
+      const { unmount } = render(<>{renderLoader()}</>)
+      expect(screen.getByRole('status')).toBeInTheDocument()
+      unmount()
+    }
+
+    for (const loadModule of mocks.dynamicImporters)
+      await expect(loadModule()).resolves.toBeTruthy()
+
+    expect(Loading).toBeDefined()
+  })
+})
diff --git a/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/index.spec.tsx b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/index.spec.tsx
index 7819042617f..438595b42c6 100644
--- a/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/index.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/index.spec.tsx
@@ -384,6 +384,14 @@ vi.mock('../../../../viewer/media-file-preview', () => ({
   ),
 }))
 
+vi.mock('../../../../viewer/sqlite-file-preview', () => ({
+  default: ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="sqlite-preview">{downloadUrl}</div>,
+}))
+
+vi.mock('../../../../viewer/pdf-file-preview', () => ({
+  default: ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="pdf-preview">{downloadUrl}</div>,
+}))
+
 vi.mock('../../../../viewer/unsupported-file-download', () => ({
   default: ({ name, size, downloadUrl }: { name: string, size?: number, downloadUrl: string }) => (
     <div data-testid="unsupported-preview">{`${name}|${String(size)}|${downloadUrl}`}</div>
@@ -786,6 +794,73 @@ describe('FileContentPanel', () => {
       expect(mocks.useSkillFileData).toHaveBeenCalledWith('app-1', 'file-1', 'download')
     })
 
+    it('should render video preview for video files', () => {
+      mocks.fileTypeInfo = {
+        isMarkdown: false,
+        isCodeOrText: false,
+        isImage: false,
+        isVideo: true,
+        isPdf: false,
+        isSQLite: false,
+        isEditable: false,
+        isPreviewable: true,
+      }
+      mocks.fileData.downloadUrlData = { download_url: 'https://example.com/video.mp4' }
+      mocks.nodeMapData = new Map<string, AppAssetTreeView>([
+        ['file-1', createNode({ name: 'video.mp4', extension: 'mp4' })],
+      ])
+
+      render(<FileContentPanel />)
+
+      expect(screen.getByTestId('media-preview')).toHaveTextContent('video|https://example.com/video.mp4')
+    })
+
+    it('should render sqlite preview for database files', async () => {
+      mocks.fileTypeInfo = {
+        isMarkdown: false,
+        isCodeOrText: false,
+        isImage: false,
+        isVideo: false,
+        isPdf: false,
+        isSQLite: true,
+        isEditable: false,
+        isPreviewable: true,
+      }
+      mocks.fileData.downloadUrlData = { download_url: 'https://example.com/demo.db' }
+      mocks.nodeMapData = new Map<string, AppAssetTreeView>([
+        ['file-1', createNode({ name: 'demo.db', extension: 'db' })],
+      ])
+
+      render(<FileContentPanel />)
+
+      await waitFor(() => {
+        expect(screen.getByTestId('sqlite-preview')).toHaveTextContent('https://example.com/demo.db')
+      })
+    })
+
+    it('should render pdf preview for pdf files', async () => {
+      mocks.fileTypeInfo = {
+        isMarkdown: false,
+        isCodeOrText: false,
+        isImage: false,
+        isVideo: false,
+        isPdf: true,
+        isSQLite: false,
+        isEditable: false,
+        isPreviewable: true,
+      }
+      mocks.fileData.downloadUrlData = { download_url: 'https://example.com/demo.pdf' }
+      mocks.nodeMapData = new Map<string, AppAssetTreeView>([
+        ['file-1', createNode({ name: 'demo.pdf', extension: 'pdf' })],
+      ])
+
+      render(<FileContentPanel />)
+
+      await waitFor(() => {
+        expect(screen.getByTestId('pdf-preview')).toHaveTextContent('https://example.com/demo.pdf')
+      })
+    })
+
     it('should render unsupported download panel for non-previewable files', () => {
       // Arrange
       mocks.fileTypeInfo = {
diff --git a/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/utils.spec.ts b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/utils.spec.ts
new file mode 100644
index 00000000000..5eb508b8f0d
--- /dev/null
+++ b/web/app/components/workflow/skill/skill-body/panels/file-content-panel/__tests__/utils.spec.ts
@@ -0,0 +1,36 @@
+import { extractFileReferenceIds, parseSkillFileMetadata } from '../utils'
+
+describe('file-content-panel utils', () => {
+  describe('extractFileReferenceIds', () => {
+    it('should collect distinct file reference ids from rich text content', () => {
+      const content = [
+        '§[file].[app].[11111111-1111-4111-8111-111111111111]§',
+        'plain text',
+        '§[file].[app].[22222222-2222-4222-8222-222222222222]§',
+        '§[file].[app].[11111111-1111-4111-8111-111111111111]§',
+      ].join('\n')
+
+      expect([...extractFileReferenceIds(content)]).toEqual([
+        '11111111-1111-4111-8111-111111111111',
+        '22222222-2222-4222-8222-222222222222',
+      ])
+    })
+  })
+
+  describe('parseSkillFileMetadata', () => {
+    it('should return an empty object for missing and invalid metadata inputs', () => {
+      expect(parseSkillFileMetadata(undefined)).toEqual({})
+      expect(parseSkillFileMetadata(null)).toEqual({})
+      expect(parseSkillFileMetadata(1)).toEqual({})
+      expect(parseSkillFileMetadata('not-json')).toEqual({})
+      expect(parseSkillFileMetadata('"text"')).toEqual({})
+    })
+
+    it('should parse object-shaped metadata from JSON strings and objects', () => {
+      expect(parseSkillFileMetadata('{"title":"Skill"}')).toEqual({ title: 'Skill' })
+
+      const metadata = { files: { 'guide.md': { id: 'file-1' } } }
+      expect(parseSkillFileMetadata(metadata)).toBe(metadata)
+    })
+  })
+})
diff --git a/web/app/components/workflow/skill/skill-body/tabs/file-tab-item.spec.tsx b/web/app/components/workflow/skill/skill-body/tabs/__tests__/file-tab-item.spec.tsx
similarity index 98%
rename from web/app/components/workflow/skill/skill-body/tabs/file-tab-item.spec.tsx
rename to web/app/components/workflow/skill/skill-body/tabs/__tests__/file-tab-item.spec.tsx
index 46031033432..b60106f7fd4 100644
--- a/web/app/components/workflow/skill/skill-body/tabs/file-tab-item.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/tabs/__tests__/file-tab-item.spec.tsx
@@ -1,6 +1,6 @@
 import type { ComponentProps } from 'react'
 import { fireEvent, render, screen } from '@testing-library/react'
-import FileTabItem from './file-tab-item'
+import FileTabItem from '.././file-tab-item'
 
 type FileTabItemProps = ComponentProps<typeof FileTabItem>
 
diff --git a/web/app/components/workflow/skill/skill-body/tabs/file-tabs.spec.tsx b/web/app/components/workflow/skill/skill-body/tabs/__tests__/file-tabs.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/skill-body/tabs/file-tabs.spec.tsx
rename to web/app/components/workflow/skill/skill-body/tabs/__tests__/file-tabs.spec.tsx
index bf0ce19fb82..2aed4d26d11 100644
--- a/web/app/components/workflow/skill/skill-body/tabs/file-tabs.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/tabs/__tests__/file-tabs.spec.tsx
@@ -1,7 +1,7 @@
 import type { AppAssetTreeView } from '@/types/app-asset'
 import { fireEvent, render, screen } from '@testing-library/react'
-import { makeArtifactTabId, START_TAB_ID } from '../../constants'
-import FileTabs from './file-tabs'
+import { makeArtifactTabId, START_TAB_ID } from '../../../constants'
+import FileTabs from '.././file-tabs'
 
 type MockWorkflowState = {
   openTabIds: string[]
@@ -42,7 +42,7 @@ vi.mock('@/app/components/workflow/store', () => ({
   }),
 }))
 
-vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useSkillAssetNodeMap: () => ({ data: mocks.nodeMap }),
 }))
 
diff --git a/web/app/components/workflow/skill/skill-body/tabs/start-tab-item.spec.tsx b/web/app/components/workflow/skill/skill-body/tabs/__tests__/start-tab-item.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/skill-body/tabs/start-tab-item.spec.tsx
rename to web/app/components/workflow/skill/skill-body/tabs/__tests__/start-tab-item.spec.tsx
index 9bec26dc535..175d06c2515 100644
--- a/web/app/components/workflow/skill/skill-body/tabs/start-tab-item.spec.tsx
+++ b/web/app/components/workflow/skill/skill-body/tabs/__tests__/start-tab-item.spec.tsx
@@ -1,6 +1,6 @@
 import type { ComponentProps } from 'react'
 import { fireEvent, render, screen } from '@testing-library/react'
-import StartTabItem from './start-tab-item'
+import StartTabItem from '.././start-tab-item'
 
 type StartTabItemProps = ComponentProps<typeof StartTabItem>
 
diff --git a/web/app/components/workflow/skill/skill-body/tabs/file-tabs.tsx b/web/app/components/workflow/skill/skill-body/tabs/file-tabs.tsx
index a39de627b3f..e5d3c20fb29 100644
--- a/web/app/components/workflow/skill/skill-body/tabs/file-tabs.tsx
+++ b/web/app/components/workflow/skill/skill-body/tabs/file-tabs.tsx
@@ -97,7 +97,7 @@ const FileTabs = () => {
         {openTabIds.map((fileId) => {
           const isArtifact = isArtifactTab(fileId)
           const node = isArtifact ? undefined : nodeMap?.get(fileId)
-          const artifactFileName = isArtifact ? getArtifactPath(fileId).split('/').pop() ?? fileId : undefined
+          const artifactFileName = isArtifact ? getArtifactPath(fileId).split('/').pop()! : undefined
           const name = isArtifact ? artifactFileName! : (node?.name ?? fileId)
           const extension = isArtifact ? getFileExtension(artifactFileName!) : node?.extension
           const isActive = activeTabId === fileId
diff --git a/web/app/components/workflow/skill/start-tab/action-card.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/action-card.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/start-tab/action-card.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/action-card.spec.tsx
index 7bf532cfa03..a4442085f8f 100644
--- a/web/app/components/workflow/skill/start-tab/action-card.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/action-card.spec.tsx
@@ -1,5 +1,5 @@
 import { fireEvent, render, screen } from '@testing-library/react'
-import ActionCard from './action-card'
+import ActionCard from '.././action-card'
 
 describe('ActionCard', () => {
   beforeEach(() => {
diff --git a/web/app/components/workflow/skill/start-tab/create-blank-skill-modal.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/create-blank-skill-modal.spec.tsx
similarity index 74%
rename from web/app/components/workflow/skill/start-tab/create-blank-skill-modal.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/create-blank-skill-modal.spec.tsx
index f8be2f44ec4..54233c915aa 100644
--- a/web/app/components/workflow/skill/start-tab/create-blank-skill-modal.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/create-blank-skill-modal.spec.tsx
@@ -1,5 +1,5 @@
 import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import CreateBlankSkillModal from './create-blank-skill-modal'
+import CreateBlankSkillModal from '.././create-blank-skill-modal'
 
 const mocks = vi.hoisted(() => ({
   appId: 'app-1',
@@ -13,17 +13,17 @@ const mocks = vi.hoisted(() => ({
   existingNames: new Set<string>(),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useExistingSkillNames: () => ({
     data: mocks.existingNames,
   }),
 }))
 
-vi.mock('../utils/skill-upload-utils', () => ({
+vi.mock('../../utils/skill-upload-utils', () => ({
   prepareSkillUploadFile: (...args: unknown[]) => mocks.prepareSkillUploadFile(...args),
 }))
 
-vi.mock('./use-skill-batch-upload', () => ({
+vi.mock('.././use-skill-batch-upload', () => ({
   useSkillBatchUpload: () => ({
     appId: mocks.appId,
     startUpload: mocks.startUpload,
@@ -147,5 +147,44 @@ describe('CreateBlankSkillModal', () => {
         expect(mocks.uploadTree).toHaveBeenCalledTimes(1)
       })
     })
+
+    it('should trim the skill name before creating the upload payload', async () => {
+      render(<CreateBlankSkillModal isOpen onClose={vi.fn()} />)
+
+      fireEvent.change(screen.getByRole('textbox'), { target: { value: '  new-skill  ' } })
+      fireEvent.click(screen.getByRole('button', { name: /common\.operation\.create/i }))
+
+      await waitFor(() => {
+        expect(mocks.prepareSkillUploadFile).toHaveBeenCalledTimes(1)
+      })
+
+      expect(mocks.uploadTree).toHaveBeenCalledWith(expect.objectContaining({
+        tree: [
+          expect.objectContaining({
+            name: 'new-skill',
+            children: [expect.objectContaining({ name: 'SKILL.md' })],
+          }),
+        ],
+        files: expect.any(Map),
+      }))
+      const uploadFiles = mocks.uploadTree.mock.calls[0][0].files as Map<string, File>
+      expect([...uploadFiles.keys()]).toEqual(['new-skill/SKILL.md'])
+    })
+
+    it('should keep the modal locked while a skill is being created', async () => {
+      const onClose = vi.fn()
+      mocks.uploadTree.mockImplementationOnce(() => new Promise(() => {}))
+
+      render(<CreateBlankSkillModal isOpen onClose={onClose} />)
+
+      fireEvent.change(screen.getByRole('textbox'), { target: { value: 'new-skill' } })
+      fireEvent.click(screen.getByRole('button', { name: /common\.operation\.create/i }))
+
+      expect(screen.queryByRole('button', { name: /close/i })).not.toBeInTheDocument()
+      expect(screen.getByRole('button', { name: /common\.operation\.cancel/i })).toBeDisabled()
+
+      fireEvent.click(screen.getByRole('button', { name: /common\.operation\.cancel/i }))
+      expect(onClose).not.toHaveBeenCalled()
+    })
   })
 })
diff --git a/web/app/components/workflow/skill/start-tab/create-import-section.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/create-import-section.spec.tsx
similarity index 93%
rename from web/app/components/workflow/skill/start-tab/create-import-section.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/create-import-section.spec.tsx
index f75a9d6dc12..4ab02b3a963 100644
--- a/web/app/components/workflow/skill/start-tab/create-import-section.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/create-import-section.spec.tsx
@@ -1,7 +1,7 @@
 import type { App, AppSSO } from '@/types/app'
 import { fireEvent, render, screen, waitFor } from '@testing-library/react'
 import { useStore as useAppStore } from '@/app/components/app/store'
-import CreateImportSection from './create-import-section'
+import CreateImportSection from '.././create-import-section'
 
 type MockWorkflowState = {
   setUploadStatus: ReturnType<typeof vi.fn>
@@ -26,13 +26,13 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useExistingSkillNames: () => ({
     data: mocks.existingNames,
   }),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-tree-collaboration', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mocks.emitTreeUpdate,
 }))
 
diff --git a/web/app/components/workflow/skill/start-tab/file-explorer-intro.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/file-explorer-intro.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/start-tab/file-explorer-intro.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/file-explorer-intro.spec.tsx
index d6673c466f6..f1d65b2e1db 100644
--- a/web/app/components/workflow/skill/start-tab/file-explorer-intro.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/file-explorer-intro.spec.tsx
@@ -1,6 +1,6 @@
 import type { ReactNode } from 'react'
 import { render, screen } from '@testing-library/react'
-import FileExplorerIntro from './file-explorer-intro'
+import FileExplorerIntro from '.././file-explorer-intro'
 
 vi.mock('react-i18next', () => ({
   Trans: ({ i18nKey, ns, components }: {
diff --git a/web/app/components/workflow/skill/start-tab/import-skill-modal.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/import-skill-modal.spec.tsx
similarity index 84%
rename from web/app/components/workflow/skill/start-tab/import-skill-modal.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/import-skill-modal.spec.tsx
index 49f2e0ad3c3..8a7ead292e5 100644
--- a/web/app/components/workflow/skill/start-tab/import-skill-modal.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/import-skill-modal.spec.tsx
@@ -1,6 +1,6 @@
 import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import { ZipValidationError } from '../utils/zip-extract'
-import ImportSkillModal from './import-skill-modal'
+import { ZipValidationError } from '../../utils/zip-extract'
+import ImportSkillModal from '.././import-skill-modal'
 
 const mocks = vi.hoisted(() => ({
   appId: 'app-1',
@@ -16,7 +16,7 @@ const mocks = vi.hoisted(() => ({
   existingNames: new Set<string>(),
 }))
 
-vi.mock('../utils/zip-extract', () => {
+vi.mock('../../utils/zip-extract', () => {
   class MockZipValidationError extends Error {
     code: string
 
@@ -33,17 +33,17 @@ vi.mock('../utils/zip-extract', () => {
   }
 })
 
-vi.mock('../utils/zip-to-upload-tree', () => ({
+vi.mock('../../utils/zip-to-upload-tree', () => ({
   buildUploadDataFromZip: (...args: unknown[]) => mocks.buildUploadDataFromZip(...args),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useExistingSkillNames: () => ({
     data: mocks.existingNames,
   }),
 }))
 
-vi.mock('./use-skill-batch-upload', () => ({
+vi.mock('.././use-skill-batch-upload', () => ({
   useSkillBatchUpload: () => ({
     appId: mocks.appId,
     startUpload: mocks.startUpload,
@@ -118,6 +118,17 @@ describe('ImportSkillModal', () => {
       expect(screen.getByRole('button', { name: /workflow\.skill\.startTab\.importModal\.importButton/i })).not.toBeDisabled()
     })
 
+    it('should format small files in bytes and large files in megabytes', () => {
+      const { rerender } = render(<ImportSkillModal isOpen onClose={vi.fn()} />)
+
+      selectFile(createZipFile('tiny.zip', 512))
+      expect(screen.getByText('512 B')).toBeInTheDocument()
+
+      rerender(<ImportSkillModal isOpen onClose={vi.fn()} />)
+      selectFile(createZipFile('large.zip', 2 * 1024 * 1024))
+      expect(screen.getByText('2.0 MB')).toBeInTheDocument()
+    })
+
     it('should select a zip file when it is dropped on the drop zone', () => {
       render(<ImportSkillModal isOpen onClose={vi.fn()} />)
 
@@ -275,5 +286,34 @@ describe('ImportSkillModal', () => {
       expect(mocks.toastError).toHaveBeenCalledWith('workflow.skill.startTab.importModal.errorInvalidZip')
       expect(mocks.toastSuccess).not.toHaveBeenCalled()
     })
+
+    it('should keep the modal locked while an import is in progress', async () => {
+      const onClose = vi.fn()
+      let resolveArrayBuffer!: (value: ArrayBuffer) => void
+      const file = createZipFile('pending.zip')
+      Object.defineProperty(file, 'arrayBuffer', {
+        value: vi.fn().mockImplementation(() => new Promise<ArrayBuffer>((resolve) => {
+          resolveArrayBuffer = resolve
+        })),
+        configurable: true,
+      })
+
+      render(<ImportSkillModal isOpen onClose={onClose} />)
+      selectFile(file)
+      fireEvent.click(screen.getByRole('button', { name: /workflow\.skill\.startTab\.importModal\.importButton/i }))
+
+      expect(screen.queryByRole('button', { name: /close/i })).not.toBeInTheDocument()
+      expect(screen.getByRole('button', { name: /common\.operation\.cancel/i })).toBeDisabled()
+
+      fireEvent.click(screen.getByRole('button', { name: /common\.operation\.cancel/i }))
+      expect(onClose).not.toHaveBeenCalled()
+
+      resolveArrayBuffer(new ArrayBuffer(8))
+      mocks.extractAndValidateZip.mockRejectedValueOnce(new Error('unknown'))
+
+      await waitFor(() => {
+        expect(mocks.failUpload).toHaveBeenCalledTimes(1)
+      })
+    })
   })
 })
diff --git a/web/app/components/workflow/skill/start-tab/index.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/index.spec.tsx
similarity index 92%
rename from web/app/components/workflow/skill/start-tab/index.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/index.spec.tsx
index c3769ab00a2..2af7702b576 100644
--- a/web/app/components/workflow/skill/start-tab/index.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/index.spec.tsx
@@ -1,7 +1,7 @@
 import type { App, AppSSO } from '@/types/app'
 import { render, screen } from '@testing-library/react'
 import { useStore as useAppStore } from '@/app/components/app/store'
-import StartTabContent from './index'
+import StartTabContent from '.././index'
 
 type MockWorkflowState = {
   setUploadStatus: ReturnType<typeof vi.fn>
@@ -26,13 +26,13 @@ vi.mock('@/service/use-app-asset', () => ({
   }),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useExistingSkillNames: () => ({
     data: mocks.existingNames,
   }),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-tree-collaboration', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-tree-collaboration', () => ({
   useSkillTreeUpdateEmitter: () => mocks.emitTreeUpdate,
 }))
 
diff --git a/web/app/components/workflow/skill/start-tab/section-header.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/section-header.spec.tsx
similarity index 96%
rename from web/app/components/workflow/skill/start-tab/section-header.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/section-header.spec.tsx
index ef811070c1b..df80f7530df 100644
--- a/web/app/components/workflow/skill/start-tab/section-header.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/section-header.spec.tsx
@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react'
-import SectionHeader from './section-header'
+import SectionHeader from '.././section-header'
 
 describe('SectionHeader', () => {
   beforeEach(() => {
diff --git a/web/app/components/workflow/skill/start-tab/skill-templates-section.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/skill-templates-section.spec.tsx
similarity index 94%
rename from web/app/components/workflow/skill/start-tab/skill-templates-section.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/skill-templates-section.spec.tsx
index cfac1035828..45f16075a02 100644
--- a/web/app/components/workflow/skill/start-tab/skill-templates-section.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/skill-templates-section.spec.tsx
@@ -1,5 +1,5 @@
 import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import SkillTemplatesSection from './skill-templates-section'
+import SkillTemplatesSection from '.././skill-templates-section'
 
 type TemplateEntry = {
   id: string
@@ -19,21 +19,21 @@ const mocks = vi.hoisted(() => ({
   existingNames: new Set<string>(),
 }))
 
-vi.mock('./templates/registry', () => ({
+vi.mock('.././templates/registry', () => ({
   SKILL_TEMPLATES: mocks.templates,
 }))
 
-vi.mock('./templates/template-to-upload', () => ({
+vi.mock('.././templates/template-to-upload', () => ({
   buildUploadDataFromTemplate: (...args: unknown[]) => mocks.buildUploadDataFromTemplate(...args),
 }))
 
-vi.mock('../hooks/file-tree/data/use-skill-asset-tree', () => ({
+vi.mock('../../hooks/file-tree/data/use-skill-asset-tree', () => ({
   useExistingSkillNames: () => ({
     data: mocks.existingNames,
   }),
 }))
 
-vi.mock('./use-skill-batch-upload', () => ({
+vi.mock('.././use-skill-batch-upload', () => ({
   useSkillBatchUpload: () => ({
     appId: mocks.appId,
     startUpload: mocks.startUpload,
diff --git a/web/app/components/workflow/skill/start-tab/template-card.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/template-card.spec.tsx
similarity index 95%
rename from web/app/components/workflow/skill/start-tab/template-card.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/template-card.spec.tsx
index db4e78797ab..64c62d459ee 100644
--- a/web/app/components/workflow/skill/start-tab/template-card.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/template-card.spec.tsx
@@ -1,6 +1,6 @@
-import type { SkillTemplateSummary } from './templates/types'
+import type { SkillTemplateSummary } from '.././templates/types'
 import { fireEvent, render, screen } from '@testing-library/react'
-import TemplateCard from './template-card'
+import TemplateCard from '.././template-card'
 
 const createTemplate = (overrides: Partial<SkillTemplateSummary> = {}): SkillTemplateSummary => ({
   id: 'docx',
diff --git a/web/app/components/workflow/skill/start-tab/template-search.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/template-search.spec.tsx
similarity index 97%
rename from web/app/components/workflow/skill/start-tab/template-search.spec.tsx
rename to web/app/components/workflow/skill/start-tab/__tests__/template-search.spec.tsx
index f0cb3fb0a0d..5692122dc6f 100644
--- a/web/app/components/workflow/skill/start-tab/template-search.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/template-search.spec.tsx
@@ -1,5 +1,5 @@
 import { fireEvent, render, screen } from '@testing-library/react'
-import TemplateSearch from './template-search'
+import TemplateSearch from '.././template-search'
 
 describe('TemplateSearch', () => {
   beforeEach(() => {
diff --git a/web/app/components/workflow/skill/start-tab/__tests__/use-skill-batch-upload.spec.tsx b/web/app/components/workflow/skill/start-tab/__tests__/use-skill-batch-upload.spec.tsx
index d1203b2aed4..30ed2155b3d 100644
--- a/web/app/components/workflow/skill/start-tab/__tests__/use-skill-batch-upload.spec.tsx
+++ b/web/app/components/workflow/skill/start-tab/__tests__/use-skill-batch-upload.spec.tsx
@@ -56,6 +56,16 @@ describe('useSkillBatchUpload', () => {
       expect(mocks.workflowState.setUploadProgress).toHaveBeenCalledWith({ uploaded: 0, total: 3, failed: 0 })
     })
 
+    it('should clamp negative totals to zero when starting an upload', () => {
+      const { result } = renderHook(() => useSkillBatchUpload())
+
+      act(() => {
+        result.current.startUpload(-2)
+      })
+
+      expect(mocks.workflowState.setUploadProgress).toHaveBeenCalledWith({ uploaded: 0, total: 0, failed: 0 })
+    })
+
     it('should update upload progress through the shared helper', () => {
       const { result } = renderHook(() => useSkillBatchUpload())
 
@@ -65,6 +75,16 @@ describe('useSkillBatchUpload', () => {
 
       expect(mocks.workflowState.setUploadProgress).toHaveBeenCalledWith({ uploaded: 2, total: 5, failed: 0 })
     })
+
+    it('should mark the upload as failed through the shared helper', () => {
+      const { result } = renderHook(() => useSkillBatchUpload())
+
+      act(() => {
+        result.current.failUpload()
+      })
+
+      expect(mocks.workflowState.setUploadStatus).toHaveBeenCalledWith('partial_error')
+    })
   })
 
   describe('Tree Upload', () => {
@@ -142,5 +162,25 @@ describe('useSkillBatchUpload', () => {
       expect(mocks.workflowState.openTab).toHaveBeenCalledWith('skill-md-id', { pinned: true })
       expect(openedId).toBe('skill-md-id')
     })
+
+    it('should return null when no skill document exists in the created nodes', () => {
+      const { result } = renderHook(() => useSkillBatchUpload())
+
+      let openedId: string | null = 'placeholder'
+      act(() => {
+        openedId = result.current.openCreatedSkillDocument([
+          {
+            id: 'folder-id',
+            name: 'alpha',
+            node_type: 'folder',
+            size: 0,
+            children: [],
+          },
+        ])
+      })
+
+      expect(mocks.workflowState.openTab).not.toHaveBeenCalled()
+      expect(openedId).toBeNull()
+    })
   })
 })
diff --git a/web/app/components/workflow/skill/start-tab/templates/registry.spec.ts b/web/app/components/workflow/skill/start-tab/templates/__tests__/registry.spec.ts
similarity index 93%
rename from web/app/components/workflow/skill/start-tab/templates/registry.spec.ts
rename to web/app/components/workflow/skill/start-tab/templates/__tests__/registry.spec.ts
index 0bc4605d5de..a1cfff65e28 100644
--- a/web/app/components/workflow/skill/start-tab/templates/registry.spec.ts
+++ b/web/app/components/workflow/skill/start-tab/templates/__tests__/registry.spec.ts
@@ -1,5 +1,5 @@
-import type { SkillTemplateNode } from './types'
-import { SKILL_TEMPLATES } from './registry'
+import type { SkillTemplateNode } from '.././types'
+import { SKILL_TEMPLATES } from '.././registry'
 
 const countFiles = (nodes: SkillTemplateNode[]): number => {
   return nodes.reduce((acc, node) => {
diff --git a/web/app/components/workflow/skill/start-tab/templates/template-to-upload.spec.ts b/web/app/components/workflow/skill/start-tab/templates/__tests__/template-to-upload.spec.ts
similarity index 92%
rename from web/app/components/workflow/skill/start-tab/templates/template-to-upload.spec.ts
rename to web/app/components/workflow/skill/start-tab/templates/__tests__/template-to-upload.spec.ts
index fd57d6d433c..4cc0e2c78f3 100644
--- a/web/app/components/workflow/skill/start-tab/templates/template-to-upload.spec.ts
+++ b/web/app/components/workflow/skill/start-tab/templates/__tests__/template-to-upload.spec.ts
@@ -1,11 +1,11 @@
-import type { SkillTemplateNode } from './types'
-import { buildUploadDataFromTemplate } from './template-to-upload'
+import type { SkillTemplateNode } from '.././types'
+import { buildUploadDataFromTemplate } from '.././template-to-upload'
 
 const mocks = vi.hoisted(() => ({
   prepareSkillUploadFile: vi.fn(),
 }))
 
-vi.mock('../../utils/skill-upload-utils', () => ({
+vi.mock('../../../utils/skill-upload-utils', () => ({
   prepareSkillUploadFile: (...args: unknown[]) => mocks.prepareSkillUploadFile(...args),
 }))
 
diff --git a/web/app/components/workflow/skill/start-tab/templates/skills/__tests__/index.spec.ts b/web/app/components/workflow/skill/start-tab/templates/skills/__tests__/index.spec.ts
new file mode 100644
index 00000000000..1bb2d51efe8
--- /dev/null
+++ b/web/app/components/workflow/skill/start-tab/templates/skills/__tests__/index.spec.ts
@@ -0,0 +1,59 @@
+import algorithmicArt from '../algorithmic-art'
+import brandGuidelines from '../brand-guidelines'
+import canvasDesign from '../canvas-design'
+import claudeApi from '../claude-api'
+import docCoauthoring from '../doc-coauthoring'
+import docx from '../docx'
+import frontendDesign from '../frontend-design'
+import internalComms from '../internal-comms'
+import mcpBuilder from '../mcp-builder'
+import pdf from '../pdf'
+import pptx from '../pptx'
+import skillCreator from '../skill-creator'
+import slackGifCreator from '../slack-gif-creator'
+import themeFactory from '../theme-factory'
+import webArtifactsBuilder from '../web-artifacts-builder'
+import webappTesting from '../webapp-testing'
+import xlsx from '../xlsx'
+import { SKILL_TEMPLATES } from '../../registry'
+import type { SkillTemplateNode } from '../../types'
+
+const countFiles = (nodes: SkillTemplateNode[]): number => {
+  return nodes.reduce((count, node) => {
+    if (node.node_type === 'file')
+      return count + 1
+    return count + countFiles(node.children)
+  }, 0)
+}
+
+const templates = [
+  { id: 'algorithmic-art', nodes: algorithmicArt },
+  { id: 'brand-guidelines', nodes: brandGuidelines },
+  { id: 'canvas-design', nodes: canvasDesign },
+  { id: 'claude-api', nodes: claudeApi },
+  { id: 'doc-coauthoring', nodes: docCoauthoring },
+  { id: 'docx', nodes: docx },
+  { id: 'frontend-design', nodes: frontendDesign },
+  { id: 'internal-comms', nodes: internalComms },
+  { id: 'mcp-builder', nodes: mcpBuilder },
+  { id: 'pdf', nodes: pdf },
+  { id: 'pptx', nodes: pptx },
+  { id: 'skill-creator', nodes: skillCreator },
+  { id: 'slack-gif-creator', nodes: slackGifCreator },
+  { id: 'theme-factory', nodes: themeFactory },
+  { id: 'web-artifacts-builder', nodes: webArtifactsBuilder },
+  { id: 'webapp-testing', nodes: webappTesting },
+  { id: 'xlsx', nodes: xlsx },
+]
+
+describe('skill template files', () => {
+  it.each(templates)('should export a non-empty tree for %s', ({ id, nodes }) => {
+    expect(nodes.length).toBeGreaterThan(0)
+    expect(nodes.every(node => Boolean(node.name))).toBe(true)
+
+    const template = SKILL_TEMPLATES.find(item => item.id === id)
+
+    expect(template).toBeDefined()
+    expect(countFiles(nodes)).toBe(template?.fileCount)
+  })
+})
diff --git a/web/app/components/workflow/skill/utils/__tests__/drag-utils.spec.ts b/web/app/components/workflow/skill/utils/__tests__/drag-utils.spec.ts
new file mode 100644
index 00000000000..bab2b261543
--- /dev/null
+++ b/web/app/components/workflow/skill/utils/__tests__/drag-utils.spec.ts
@@ -0,0 +1,41 @@
+import type * as React from 'react'
+import { INTERNAL_NODE_DRAG_TYPE } from '../../constants'
+import {
+  getDragActionType,
+  isDragEvent,
+  isFileDrag,
+  isNodeDrag,
+} from '../drag-utils'
+
+const createDragEvent = (types: string[]): React.DragEvent => ({
+  dataTransfer: {
+    types,
+  },
+} as unknown as React.DragEvent)
+
+describe('drag-utils', () => {
+  it('should detect external file drags', () => {
+    const event = createDragEvent(['Files'])
+
+    expect(isFileDrag(event)).toBe(true)
+    expect(isNodeDrag(event)).toBe(false)
+    expect(isDragEvent(event)).toBe(true)
+    expect(getDragActionType(event)).toBe('upload')
+  })
+
+  it('should detect internal node drags', () => {
+    const event = createDragEvent([INTERNAL_NODE_DRAG_TYPE])
+
+    expect(isFileDrag(event)).toBe(false)
+    expect(isNodeDrag(event)).toBe(true)
+    expect(isDragEvent(event)).toBe(true)
+    expect(getDragActionType(event)).toBe('move')
+  })
+
+  it('should reject unsupported drag payloads', () => {
+    const event = createDragEvent(['text/plain'])
+
+    expect(isDragEvent(event)).toBe(false)
+    expect(getDragActionType(event)).toBeNull()
+  })
+})
diff --git a/web/app/components/workflow/skill/utils/__tests__/file-utils.spec.ts b/web/app/components/workflow/skill/utils/__tests__/file-utils.spec.ts
new file mode 100644
index 00000000000..b4683af7ac9
--- /dev/null
+++ b/web/app/components/workflow/skill/utils/__tests__/file-utils.spec.ts
@@ -0,0 +1,82 @@
+import { FileAppearanceTypeEnum } from '@/app/components/base/file-uploader/types'
+import {
+  getFileExtension,
+  getFileIconType,
+  getFileLanguage,
+  isBinaryFile,
+  isImageFile,
+  isMarkdownFile,
+  isPdfFile,
+  isSQLiteFile,
+  isTextLikeFile,
+  isVideoFile,
+} from '../file-utils'
+
+describe('file-utils', () => {
+  describe('getFileExtension', () => {
+    it('should prefer the explicit extension and normalize casing', () => {
+      expect(getFileExtension('note.txt', '.MD')).toBe('md')
+    })
+
+    it('should derive the extension from the file name', () => {
+      expect(getFileExtension('archive.TAR.GZ')).toBe('gz')
+    })
+
+    it('should return an empty string when no name is available', () => {
+      expect(getFileExtension()).toBe('')
+    })
+  })
+
+  describe('getFileIconType', () => {
+    it('should resolve media, document, and database icon types', () => {
+      expect(getFileIconType('cover.png')).toBe(FileAppearanceTypeEnum.image)
+      expect(getFileIconType('anim.gif')).toBe(FileAppearanceTypeEnum.image)
+      expect(getFileIconType('clip.mp4')).toBe(FileAppearanceTypeEnum.video)
+      expect(getFileIconType('podcast.mp3')).toBe(FileAppearanceTypeEnum.audio)
+      expect(getFileIconType('notes.md')).toBe(FileAppearanceTypeEnum.markdown)
+      expect(getFileIconType('report.docx')).toBe(FileAppearanceTypeEnum.word)
+      expect(getFileIconType('schema.ts')).toBe(FileAppearanceTypeEnum.code)
+      expect(getFileIconType('sheet.xlsx')).toBe(FileAppearanceTypeEnum.excel)
+      expect(getFileIconType('slides.pptx')).toBe(FileAppearanceTypeEnum.ppt)
+      expect(getFileIconType('data.sqlite')).toBe(FileAppearanceTypeEnum.database)
+      expect(getFileIconType('unknown.bin')).toBe(FileAppearanceTypeEnum.document)
+    })
+
+    it('should let the explicit extension override the file name', () => {
+      expect(getFileIconType('README', '.pdf')).toBe(FileAppearanceTypeEnum.pdf)
+    })
+  })
+
+  describe('type guards', () => {
+    it('should classify markdown, image, video, sqlite, pdf, and binary files', () => {
+      expect(isMarkdownFile('mdx')).toBe(true)
+      expect(isImageFile('svg')).toBe(true)
+      expect(isVideoFile('webm')).toBe(true)
+      expect(isSQLiteFile('sqlite3')).toBe(true)
+      expect(isPdfFile('pdf')).toBe(true)
+      expect(isBinaryFile('docx')).toBe(true)
+    })
+
+    it('should detect text-like files by excluding binary and preview-only formats', () => {
+      expect(isTextLikeFile('ts')).toBe(true)
+      expect(isTextLikeFile('svg')).toBe(false)
+      expect(isTextLikeFile('mp4')).toBe(false)
+      expect(isTextLikeFile('pdf')).toBe(false)
+      expect(isTextLikeFile('zip')).toBe(false)
+    })
+  })
+
+  describe('getFileLanguage', () => {
+    it('should map supported extensions to editor languages', () => {
+      expect(getFileLanguage('index.tsx')).toBe('typescript')
+      expect(getFileLanguage('config.yml')).toBe('yaml')
+      expect(getFileLanguage('script.sh')).toBe('shell')
+      expect(getFileLanguage('template.html')).toBe('html')
+      expect(getFileLanguage('query.sql')).toBe('sql')
+    })
+
+    it('should fall back to plaintext for unknown extensions', () => {
+      expect(getFileLanguage('LICENSE')).toBe('plaintext')
+    })
+  })
+})
diff --git a/web/app/components/workflow/skill/utils/__tests__/skill-upload-utils.spec.ts b/web/app/components/workflow/skill/utils/__tests__/skill-upload-utils.spec.ts
new file mode 100644
index 00000000000..eda97ce54b9
--- /dev/null
+++ b/web/app/components/workflow/skill/utils/__tests__/skill-upload-utils.spec.ts
@@ -0,0 +1,37 @@
+import { prepareSkillUploadFile } from '../skill-upload-utils'
+
+describe('skill-upload-utils', () => {
+  it('should wrap markdown files into the skill upload payload', async () => {
+    const file = new File(['# Skill body'], 'SKILL.md', { type: 'text/markdown' })
+
+    const prepared = await prepareSkillUploadFile(file)
+
+    expect(prepared).not.toBe(file)
+    expect(prepared.name).toBe('SKILL.md')
+    expect(prepared.type).toBe('text/markdown')
+    await expect(prepared.text()).resolves.toBe(JSON.stringify({
+      content: '# Skill body',
+      metadata: {},
+    }))
+  })
+
+  it('should keep non-markdown files untouched', async () => {
+    const file = new File(['binary'], 'archive.zip', { type: 'application/zip' })
+
+    const prepared = await prepareSkillUploadFile(file)
+
+    expect(prepared).toBe(file)
+  })
+
+  it('should fallback to text/plain when the source markdown file has no explicit type', async () => {
+    const file = new File(['# Skill body'], 'SKILL.md')
+
+    const prepared = await prepareSkillUploadFile(file)
+
+    expect(prepared.type).toBe('text/plain')
+    await expect(prepared.text()).resolves.toBe(JSON.stringify({
+      content: '# Skill body',
+      metadata: {},
+    }))
+  })
+})
diff --git a/web/app/components/workflow/skill/utils/__tests__/tree-utils.spec.ts b/web/app/components/workflow/skill/utils/__tests__/tree-utils.spec.ts
new file mode 100644
index 00000000000..951687114ea
--- /dev/null
+++ b/web/app/components/workflow/skill/utils/__tests__/tree-utils.spec.ts
@@ -0,0 +1,166 @@
+import type { AppAssetTreeView } from '@/types/app-asset'
+import { ROOT_ID } from '../../constants'
+import {
+  buildNodeMap,
+  createDraftTreeNode,
+  findNodeById,
+  flattenMatchingNodes,
+  getAllDescendantFileIds,
+  getAncestorIds,
+  getTargetFolderIdFromSelection,
+  insertDraftTreeNode,
+  isDescendantOf,
+  isRootId,
+  toApiParentId,
+  toOpensObject,
+} from '../tree-utils'
+
+const tree: AppAssetTreeView[] = [
+  {
+    id: 'folder-a',
+    node_type: 'folder',
+    name: 'folder-a',
+    path: '/folder-a',
+    extension: '',
+    size: 0,
+    children: [
+      {
+        id: 'file-1',
+        node_type: 'file',
+        name: 'guide.md',
+        path: '/folder-a/guide.md',
+        extension: 'md',
+        size: 10,
+        children: [],
+      },
+      {
+        id: 'folder-b',
+        node_type: 'folder',
+        name: 'folder-b',
+        path: '/folder-a/folder-b',
+        extension: '',
+        size: 0,
+        children: [
+          {
+            id: 'file-2',
+            node_type: 'file',
+            name: 'data.json',
+            path: '/folder-a/folder-b/data.json',
+            extension: 'json',
+            size: 20,
+            children: [],
+          },
+        ],
+      },
+    ],
+  },
+  {
+    id: 'empty-folder',
+    node_type: 'folder',
+    name: 'empty-folder',
+    path: '/empty-folder',
+    extension: '',
+    size: 0,
+    children: [],
+  },
+]
+
+describe('tree-utils', () => {
+  describe('root helpers', () => {
+    it('should normalize root identifiers for API calls', () => {
+      expect(isRootId(undefined)).toBe(true)
+      expect(isRootId(ROOT_ID)).toBe(true)
+      expect(isRootId('folder-a')).toBe(false)
+      expect(toApiParentId(ROOT_ID)).toBeNull()
+      expect(toApiParentId('folder-a')).toBe('folder-a')
+    })
+
+    it('should convert expanded ids into the opens object expected by the tree', () => {
+      expect(toOpensObject(new Set(['folder-a', 'folder-b']))).toEqual({
+        'folder-a': true,
+        'folder-b': true,
+      })
+    })
+  })
+
+  describe('tree traversal', () => {
+    it('should build node maps, find nodes, and collect ancestors', () => {
+      const nodeMap = buildNodeMap(tree)
+
+      expect(nodeMap.get('file-2')?.name).toBe('data.json')
+      expect(findNodeById(tree, 'folder-b')?.name).toBe('folder-b')
+      expect(findNodeById(tree, 'missing')).toBeNull()
+      expect(getAncestorIds('file-2', tree)).toEqual(['folder-a', 'folder-b'])
+      expect(getAncestorIds('missing', tree)).toEqual([])
+    })
+
+    it('should collect descendant file ids for folders and single files', () => {
+      expect(getAllDescendantFileIds('folder-a', tree)).toEqual(['file-1', 'file-2'])
+      expect(getAllDescendantFileIds('file-1', tree)).toEqual(['file-1'])
+      expect(getAllDescendantFileIds('missing', tree)).toEqual([])
+    })
+
+    it('should resolve descendant relationships and target folders from selections', () => {
+      expect(isDescendantOf('file-2', 'folder-a', tree)).toBe(true)
+      expect(isDescendantOf('folder-a', 'folder-a', tree)).toBe(true)
+      expect(isDescendantOf('file-1', 'empty-folder', tree)).toBe(false)
+      expect(isDescendantOf(null, 'folder-a', tree)).toBe(false)
+
+      expect(getTargetFolderIdFromSelection(null, tree)).toBe(ROOT_ID)
+      expect(getTargetFolderIdFromSelection('folder-a', tree)).toBe('folder-a')
+      expect(getTargetFolderIdFromSelection('file-2', tree)).toBe('folder-b')
+      expect(getTargetFolderIdFromSelection('missing', tree)).toBe(ROOT_ID)
+    })
+  })
+
+  describe('draft helpers', () => {
+    it('should create and insert draft nodes at root or under a matching folder', () => {
+      const draftFile = createDraftTreeNode({ id: 'draft-file', nodeType: 'file' })
+      const draftFolder = createDraftTreeNode({ id: 'draft-folder', nodeType: 'folder' })
+
+      expect(draftFile).toEqual({
+        id: 'draft-file',
+        node_type: 'file',
+        name: '',
+        path: '',
+        extension: '',
+        size: 0,
+        children: [],
+      })
+
+      expect(insertDraftTreeNode(tree, null, draftFile)[0].id).toBe('draft-file')
+
+      const inserted = insertDraftTreeNode(tree, 'folder-a', draftFolder)
+      expect(inserted[0].children[0].id).toBe('draft-folder')
+
+      const fallbackToRoot = insertDraftTreeNode(tree, 'missing', draftFile)
+      expect(fallbackToRoot[0].id).toBe('draft-file')
+    })
+  })
+
+  describe('search flattening', () => {
+    it('should flatten matching nodes and include their parent paths', () => {
+      expect(flattenMatchingNodes(tree, '')).toEqual([])
+      expect(flattenMatchingNodes(tree, 'guide')).toEqual([
+        {
+          node: tree[0].children[0],
+          parentPath: 'folder-a',
+        },
+      ])
+      expect(flattenMatchingNodes(tree, 'folder')).toEqual([
+        {
+          node: tree[0],
+          parentPath: '',
+        },
+        {
+          node: tree[0].children[1],
+          parentPath: 'folder-a',
+        },
+        {
+          node: tree[1],
+          parentPath: '',
+        },
+      ])
+    })
+  })
+})
diff --git a/web/app/components/workflow/skill/utils/__tests__/zip-extract.spec.ts b/web/app/components/workflow/skill/utils/__tests__/zip-extract.spec.ts
new file mode 100644
index 00000000000..ed2a049a450
--- /dev/null
+++ b/web/app/components/workflow/skill/utils/__tests__/zip-extract.spec.ts
@@ -0,0 +1,213 @@
+import type { ZipValidationError } from '../zip-extract'
+import { extractAndValidateZip } from '../zip-extract'
+
+type MockZipEntry = {
+  name: string
+  originalSize: number
+}
+
+type MockUnzipScenario = {
+  entries?: MockZipEntry[]
+  result?: Record<string, Uint8Array>
+  error?: Error
+  errorAfterFilter?: Error
+}
+
+const mocks = vi.hoisted(() => ({
+  scenario: null as MockUnzipScenario | null,
+}))
+
+const expectZipValidationError = async (promise: Promise<unknown>, code: ZipValidationError['code']) => {
+  await expect(promise).rejects.toMatchObject({
+    code,
+  } satisfies Partial<ZipValidationError>)
+}
+
+vi.mock('fflate', () => ({
+  unzip: (
+    _data: Uint8Array,
+    options: { filter: (file: MockZipEntry) => boolean },
+    callback: (error: Error | null, result: Record<string, Uint8Array>) => void,
+  ) => {
+    const scenario = mocks.scenario
+
+    if (!scenario) {
+      callback(new Error('missing scenario'), {})
+      return
+    }
+
+    if (scenario.error) {
+      callback(scenario.error, {})
+      return
+    }
+
+    const filteredResult = Object.fromEntries(
+      (scenario.entries ?? [])
+        .filter(entry => options.filter(entry))
+        .map((entry) => {
+          const data = scenario.result?.[entry.name] ?? new Uint8Array(entry.originalSize)
+          return [entry.name, data]
+        }),
+    )
+
+    if (scenario.errorAfterFilter) {
+      callback(scenario.errorAfterFilter, {})
+      return
+    }
+
+    callback(null, filteredResult)
+  },
+}))
+
+describe('zip-extract', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.scenario = null
+  })
+
+  it('should extract a zip with one root folder and ignore system files', async () => {
+    mocks.scenario = {
+      entries: [
+        { name: 'demo-skill/SKILL.md', originalSize: 7 },
+        { name: 'demo-skill/assets/logo.txt', originalSize: 4 },
+        { name: '__MACOSX/demo-skill/.DS_Store', originalSize: 1 },
+        { name: 'demo-skill/.DS_Store', originalSize: 1 },
+      ],
+      result: {
+        'demo-skill/SKILL.md': new TextEncoder().encode('# Skill'),
+        'demo-skill/assets/logo.txt': new TextEncoder().encode('logo'),
+      },
+    }
+
+    const result = await extractAndValidateZip(new ArrayBuffer(8))
+
+    expect(result.rootFolderName).toBe('demo-skill')
+    expect([...result.files.keys()]).toEqual([
+      'demo-skill/SKILL.md',
+      'demo-skill/assets/logo.txt',
+    ])
+  })
+
+  it('should reject archives without files', async () => {
+    mocks.scenario = {
+      entries: [],
+      result: {},
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'empty_zip')
+  })
+
+  it('should reject archives with multiple root folders', async () => {
+    mocks.scenario = {
+      entries: [
+        { name: 'demo-a/SKILL.md', originalSize: 3 },
+        { name: 'demo-b/SKILL.md', originalSize: 3 },
+      ],
+      result: {
+        'demo-a/SKILL.md': new TextEncoder().encode('# A'),
+        'demo-b/SKILL.md': new TextEncoder().encode('# B'),
+      },
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'no_root_folder')
+  })
+
+  it('should reject archives with unsafe paths', async () => {
+    mocks.scenario = {
+      entries: [{ name: 'demo-skill/../evil.txt', originalSize: 4 }],
+      result: {},
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'path_traversal')
+  })
+
+  it('should reject archives with too many files', async () => {
+    mocks.scenario = {
+      entries: Array.from({ length: 201 }, (_, index) => ({
+        name: `demo-skill/file-${index}.txt`,
+        originalSize: 1,
+      })),
+      result: {},
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'too_many_files')
+  })
+
+  it('should reject zip files that exceed the compressed size limit before extraction', async () => {
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(51 * 1024 * 1024)), 'zip_too_large')
+  })
+
+  it('should ignore directory entries while extracting', async () => {
+    mocks.scenario = {
+      entries: [
+        { name: 'demo-skill/', originalSize: 0 },
+        { name: 'demo-skill/SKILL.md', originalSize: 7 },
+      ],
+      result: {
+        'demo-skill/SKILL.md': new TextEncoder().encode('# Skill'),
+      },
+    }
+
+    const result = await extractAndValidateZip(new ArrayBuffer(8))
+    expect([...result.files.keys()]).toEqual(['demo-skill/SKILL.md'])
+  })
+
+  it('should reject archives when filtered extracted size exceeds the estimate limit', async () => {
+    mocks.scenario = {
+      entries: [
+        { name: 'demo-skill/huge.bin', originalSize: 201 * 1024 * 1024 },
+      ],
+      result: {},
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'extracted_too_large')
+  })
+
+  it('should reject archives when extracted file data exceeds the actual size limit', async () => {
+    const huge = new Uint8Array(201 * 1024 * 1024)
+    mocks.scenario = {
+      entries: [
+        { name: 'demo-skill/huge.bin', originalSize: 1 },
+      ],
+      result: {
+        'demo-skill/huge.bin': huge,
+      },
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'extracted_too_large')
+  })
+
+  it('should reject invalid zip data', async () => {
+    mocks.scenario = {
+      error: new Error('bad zip'),
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'invalid_zip')
+  })
+
+  it('should preserve the original filter validation error when decompression fails afterward', async () => {
+    mocks.scenario = {
+      entries: [{ name: 'demo-skill/../evil.txt', originalSize: 4 }],
+      errorAfterFilter: new Error('bad zip'),
+    }
+
+    await expectZipValidationError(extractAndValidateZip(new ArrayBuffer(8)), 'path_traversal')
+  })
+
+  it('should ignore common Windows system files while extracting', async () => {
+    mocks.scenario = {
+      entries: [
+        { name: 'demo-skill/Thumbs.db', originalSize: 1 },
+        { name: 'demo-skill/desktop.ini', originalSize: 1 },
+        { name: 'demo-skill/SKILL.md', originalSize: 7 },
+      ],
+      result: {
+        'demo-skill/SKILL.md': new TextEncoder().encode('# Skill'),
+      },
+    }
+
+    const result = await extractAndValidateZip(new ArrayBuffer(8))
+
+    expect([...result.files.keys()]).toEqual(['demo-skill/SKILL.md'])
+  })
+})
diff --git a/web/app/components/workflow/skill/utils/__tests__/zip-to-upload-tree.spec.ts b/web/app/components/workflow/skill/utils/__tests__/zip-to-upload-tree.spec.ts
new file mode 100644
index 00000000000..a83e40a4b4b
--- /dev/null
+++ b/web/app/components/workflow/skill/utils/__tests__/zip-to-upload-tree.spec.ts
@@ -0,0 +1,60 @@
+import { buildUploadDataFromZip } from '../zip-to-upload-tree'
+
+const mocks = vi.hoisted(() => ({
+  prepareSkillUploadFile: vi.fn<(file: File) => Promise<File>>(),
+}))
+
+vi.mock('../skill-upload-utils', () => ({
+  prepareSkillUploadFile: (file: File) => mocks.prepareSkillUploadFile(file),
+}))
+
+describe('zip-to-upload-tree', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.prepareSkillUploadFile.mockImplementation(async file => file)
+  })
+
+  it('should convert extracted zip files into upload tree data', async () => {
+    const extracted = {
+      rootFolderName: 'demo-skill',
+      files: new Map<string, Uint8Array>([
+        ['demo-skill/SKILL.md', new Uint8Array([35, 32, 83, 107, 105, 108, 108])],
+        ['demo-skill/assets/logo.png', new Uint8Array([1, 2, 3])],
+      ]),
+    }
+
+    const result = await buildUploadDataFromZip(extracted)
+
+    expect([...result.files.keys()]).toEqual([
+      'demo-skill/SKILL.md',
+      'demo-skill/assets/logo.png',
+    ])
+    expect(result.tree).toEqual([
+      {
+        name: 'demo-skill',
+        node_type: 'folder',
+        children: [
+          {
+            name: 'SKILL.md',
+            node_type: 'file',
+            size: result.files.get('demo-skill/SKILL.md')?.size ?? 0,
+          },
+          {
+            name: 'assets',
+            node_type: 'folder',
+            children: [
+              {
+                name: 'logo.png',
+                node_type: 'file',
+                size: result.files.get('demo-skill/assets/logo.png')?.size ?? 0,
+              },
+            ],
+          },
+        ],
+      },
+    ])
+    expect(mocks.prepareSkillUploadFile).toHaveBeenCalledTimes(2)
+    expect(result.files.get('demo-skill/SKILL.md')?.type).toBe('text/markdown')
+    expect(result.files.get('demo-skill/assets/logo.png')?.type).toBe('application/octet-stream')
+  })
+})
diff --git a/web/app/components/workflow/skill/utils/file-utils.ts b/web/app/components/workflow/skill/utils/file-utils.ts
index 12c2f8dad29..d8c11fa47d5 100644
--- a/web/app/components/workflow/skill/utils/file-utils.ts
+++ b/web/app/components/workflow/skill/utils/file-utils.ts
@@ -83,7 +83,8 @@ export function getFileExtension(name?: string, extension?: string): string {
     return extension.replace(/^\./, '').toLowerCase()
   if (!name)
     return ''
-  return name.split('.').pop()?.toLowerCase() ?? ''
+  const parts = name.split('.')
+  return parts[parts.length - 1].toLowerCase()
 }
 
 const AUDIO_EXTENSIONS = ['mp3', 'm4a', 'wav', 'amr', 'mpga', 'ogg', 'flac', 'aac', 'wma', 'aiff', 'opus']
@@ -110,7 +111,7 @@ const EXTENSION_TO_ICON_TYPE = new Map<string, FileAppearanceTypeEnum>(
 )
 
 export function getFileIconType(name: string, ext?: string | null): FileAppearanceTypeEnum {
-  const extension = ext?.replace(/^\./, '').toLowerCase() ?? name.split('.').pop()?.toLowerCase() ?? ''
+  const extension = getFileExtension(name, ext ?? undefined)
   return EXTENSION_TO_ICON_TYPE.get(extension) ?? FileAppearanceTypeEnum.document
 }
 
@@ -143,7 +144,7 @@ export function isPdfFile(extension: string): boolean {
 }
 
 export function getFileLanguage(name: string): string {
-  const extension = name.split('.').pop()?.toLowerCase() ?? ''
+  const extension = getFileExtension(name)
 
   const languageMap: Record<string, string> = {
     md: 'markdown',
diff --git a/web/app/components/workflow/skill/viewer/__tests__/media-file-preview.spec.tsx b/web/app/components/workflow/skill/viewer/__tests__/media-file-preview.spec.tsx
new file mode 100644
index 00000000000..45ae57437db
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/__tests__/media-file-preview.spec.tsx
@@ -0,0 +1,22 @@
+import { render, screen } from '@testing-library/react'
+import MediaFilePreview from '../media-file-preview'
+
+describe('MediaFilePreview', () => {
+  it('should render an unavailable state when the source is missing', () => {
+    render(<MediaFilePreview type="image" src="" />)
+
+    expect(screen.getByText('workflow.skillEditor.previewUnavailable')).toBeInTheDocument()
+  })
+
+  it('should render an image preview when the type is image', () => {
+    const { container } = render(<MediaFilePreview type="image" src="https://example.com/image.png" />)
+
+    expect(container.querySelector('img')).toHaveAttribute('src', 'https://example.com/image.png')
+  })
+
+  it('should render a video preview when the type is video', () => {
+    const { container } = render(<MediaFilePreview type="video" src="https://example.com/video.mp4" />)
+
+    expect(container.querySelector('video')).toHaveAttribute('src', 'https://example.com/video.mp4')
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/__tests__/pdf-file-preview.spec.tsx b/web/app/components/workflow/skill/viewer/__tests__/pdf-file-preview.spec.tsx
new file mode 100644
index 00000000000..dd7757af14b
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/__tests__/pdf-file-preview.spec.tsx
@@ -0,0 +1,82 @@
+import type { ReactNode } from 'react'
+import { act, fireEvent, render, screen } from '@testing-library/react'
+
+import PdfFilePreview from '../pdf-file-preview'
+
+const mocks = vi.hoisted(() => ({
+  hotkeys: new Map<string, () => void>(),
+  highlighterProps: null as null | Record<string, unknown>,
+}))
+
+vi.mock('react-hotkeys-hook', () => ({
+  useHotkeys: (keys: string, callback: () => void) => {
+    mocks.hotkeys.set(keys, callback)
+  },
+}))
+
+vi.mock('react-pdf-highlighter', () => ({
+  PdfLoader: ({ children, beforeLoad }: { children: (doc: unknown) => ReactNode, beforeLoad: ReactNode }) => (
+    <div data-testid="pdf-loader">
+      {beforeLoad}
+      {children({ numPages: 1 })}
+    </div>
+  ),
+  PdfHighlighter: (props: Record<string, unknown>) => {
+    mocks.highlighterProps = props
+    return <div data-testid="pdf-highlighter" />
+  },
+}))
+
+const getScaleContainer = () => {
+  const container = document.querySelector('div[style*="transform"]') as HTMLDivElement | null
+  expect(container).toBeInTheDocument()
+  return container!
+}
+
+describe('PdfFilePreview', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.hotkeys.clear()
+    mocks.highlighterProps = null
+  })
+
+  it('should render the pdf viewer and loading state', () => {
+    render(<PdfFilePreview downloadUrl="https://example.com/demo.pdf" />)
+
+    expect(screen.getByTestId('pdf-loader')).toBeInTheDocument()
+    expect(screen.getByTestId('pdf-highlighter')).toBeInTheDocument()
+    expect(screen.getByRole('status')).toBeInTheDocument()
+  })
+
+  it('should zoom with toolbar controls and hotkeys', () => {
+    render(<PdfFilePreview downloadUrl="https://example.com/demo.pdf" />)
+
+    fireEvent.click(screen.getByRole('button', { name: 'Zoom in' }))
+    expect(getScaleContainer().getAttribute('style')).toContain('scale(1.2)')
+
+    fireEvent.click(screen.getByRole('button', { name: 'Zoom out' }))
+    expect(getScaleContainer().getAttribute('style')).toContain('scale(1)')
+
+    act(() => {
+      mocks.hotkeys.get('up')?.()
+    })
+    expect(getScaleContainer().getAttribute('style')).toContain('scale(1.2)')
+
+    act(() => {
+      mocks.hotkeys.get('down')?.()
+    })
+    expect(getScaleContainer().getAttribute('style')).toContain('scale(1)')
+  })
+
+  it('should provide the non-interactive highlighter callbacks expected by the viewer', () => {
+    render(<PdfFilePreview downloadUrl="https://example.com/demo.pdf" />)
+
+    expect(mocks.highlighterProps).toBeTruthy()
+    expect((mocks.highlighterProps?.enableAreaSelection as () => boolean)()).toBe(false)
+    expect((mocks.highlighterProps?.onSelectionFinished as () => null)()).toBeNull()
+
+    const highlight = (mocks.highlighterProps?.highlightTransform as () => ReactNode)()
+    const { container } = render(<>{highlight}</>)
+    expect(container.firstChild?.nodeName).toBe('DIV')
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/__tests__/read-only-code-preview.spec.tsx b/web/app/components/workflow/skill/viewer/__tests__/read-only-code-preview.spec.tsx
new file mode 100644
index 00000000000..4d9580b548d
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/__tests__/read-only-code-preview.spec.tsx
@@ -0,0 +1,128 @@
+import { act, render, screen } from '@testing-library/react'
+import ReadOnlyCodePreview from '../read-only-code-preview'
+
+const mocks = vi.hoisted(() => ({
+  theme: 'light',
+  loaderConfig: vi.fn(),
+  editorProps: [] as Array<Record<string, unknown>>,
+  monacoSetTheme: vi.fn(),
+}))
+
+vi.mock('@monaco-editor/react', () => ({
+  loader: {
+    config: (config: unknown) => mocks.loaderConfig(config),
+  },
+}))
+
+vi.mock('@/hooks/use-theme', () => ({
+  default: () => ({ theme: mocks.theme }),
+}))
+
+vi.mock('@/types/app', () => ({
+  Theme: { light: 'light', dark: 'dark' },
+  AgentStrategy: { functionCall: 'functionCall' },
+}))
+
+vi.mock('../../editor/code-file-editor', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.editorProps.push(props)
+    return (
+      <button
+        type="button"
+        onClick={() => (props.onMount as (editor: unknown, monaco: { editor: { setTheme: (theme: string) => void } }) => void)({}, { editor: { setTheme: mocks.monacoSetTheme } })}
+      >
+        mount-read-only-editor
+      </button>
+    )
+  },
+}))
+describe('ReadOnlyCodePreview', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.theme = 'light'
+    mocks.editorProps.length = 0
+  })
+
+  it('should render with the default theme until Monaco mounts', () => {
+    render(<ReadOnlyCodePreview value="const a = 1" language="typescript" />)
+
+    expect(mocks.editorProps[0]).toMatchObject({
+      value: 'const a = 1',
+      language: 'typescript',
+      theme: 'default-theme',
+      readOnly: true,
+    })
+  })
+
+  it('should resolve the light Monaco theme when mounted in light mode', () => {
+    render(<ReadOnlyCodePreview value="const a = 1" language="typescript" />)
+
+    act(() => {
+      screen.getByRole('button', { name: 'mount-read-only-editor' }).click()
+    })
+
+    expect(mocks.monacoSetTheme).toHaveBeenCalledWith('light')
+    expect(mocks.editorProps.at(-1)).toMatchObject({
+      theme: 'light',
+    })
+  })
+
+  it('should switch to the resolved Monaco theme after mount', () => {
+    mocks.theme = 'dark'
+
+    render(<ReadOnlyCodePreview value="const a = 1" language="typescript" />)
+
+    act(() => {
+      screen.getByRole('button', { name: 'mount-read-only-editor' }).click()
+    })
+
+    expect(mocks.monacoSetTheme).toHaveBeenCalledWith('vs-dark')
+    expect(mocks.editorProps.at(-1)).toMatchObject({
+      theme: 'vs-dark',
+    })
+  })
+
+  it('should expose a stable no-op change handler', () => {
+    render(<ReadOnlyCodePreview value="const a = 1" language="typescript" />)
+
+    expect(() => (mocks.editorProps[0].onChange as () => void)()).not.toThrow()
+  })
+
+  it('should skip Monaco path configuration when window is unavailable at import time', async () => {
+    const originalWindow = globalThis.window
+
+    vi.resetModules()
+    mocks.loaderConfig.mockClear()
+    vi.stubGlobal('window', undefined)
+
+    const readOnlyCodePreviewModule = await import('../read-only-code-preview')
+    const FreshReadOnlyCodePreview = readOnlyCodePreviewModule.default
+
+    vi.stubGlobal('window', originalWindow)
+    mocks.editorProps.length = 0
+
+    render(<FreshReadOnlyCodePreview value="const a = 1" language="typescript" />)
+
+    expect(mocks.loaderConfig).not.toHaveBeenCalled()
+  })
+
+  it('should configure Monaco asset paths when window is available at import time', async () => {
+    const originalWindow = globalThis.window
+
+    vi.resetModules()
+    mocks.loaderConfig.mockClear()
+    vi.stubGlobal('window', {
+      location: { origin: 'https://example.com' },
+    })
+
+    await import('../read-only-code-preview')
+
+    expect(mocks.loaderConfig).toHaveBeenCalledWith(expect.objectContaining({
+      paths: expect.objectContaining({
+        vs: expect.stringContaining('https://example.com'),
+      }),
+    }))
+
+    vi.stubGlobal('window', originalWindow)
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/__tests__/read-only-file-preview.spec.tsx b/web/app/components/workflow/skill/viewer/__tests__/read-only-file-preview.spec.tsx
new file mode 100644
index 00000000000..088ee980946
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/__tests__/read-only-file-preview.spec.tsx
@@ -0,0 +1,235 @@
+import { render, screen } from '@testing-library/react'
+import Loading from '@/app/components/base/loading'
+import ReadOnlyFilePreview from '../read-only-file-preview'
+
+const mocks = vi.hoisted(() => ({
+  fileTypeInfo: {
+    isMarkdown: false,
+    isCodeOrText: false,
+    isImage: false,
+    isVideo: false,
+    isPdf: false,
+    isSQLite: false,
+    isEditable: false,
+    isMediaFile: false,
+    isPreviewable: false,
+  },
+  fetchState: {
+    data: undefined as string | undefined,
+    isLoading: false,
+  },
+  getFileLanguage: vi.fn((_: string) => 'typescript'),
+  dynamicLoaders: [] as Array<() => React.ReactNode>,
+  dynamicImporters: [] as Array<() => Promise<unknown>>,
+  fetchArgs: [] as Array<string | undefined>,
+  dynamicComponents: [
+    ({ value, language }: { value: string, language: string }) => <div data-testid="code-preview">{`${language}:${value}`}</div>,
+    ({ value }: { value: string }) => <div data-testid="markdown-preview">{value}</div>,
+    ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="sqlite-preview">{downloadUrl}</div>,
+    ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="pdf-preview">{downloadUrl}</div>,
+  ],
+  dynamicIndex: 0,
+}))
+
+vi.mock('@/next/dynamic', () => ({
+  default: (loader: () => Promise<unknown>, options?: { loading?: () => React.ReactNode }) => {
+    mocks.dynamicImporters.push(loader)
+    if (options?.loading)
+      mocks.dynamicLoaders.push(options.loading)
+    return mocks.dynamicComponents[mocks.dynamicIndex++]
+  },
+}))
+
+vi.mock('../media-file-preview', () => ({
+  default: ({ type, src }: { type: string, src: string }) => <div data-testid="media-preview">{`${type}:${src}`}</div>,
+}))
+
+vi.mock('../read-only-code-preview', () => ({
+  default: ({ value, language }: { value: string, language: string }) => <div data-testid="resolved-code-preview">{`${language}:${value}`}</div>,
+}))
+
+vi.mock('../read-only-markdown-preview', () => ({
+  default: ({ value }: { value: string }) => <div data-testid="resolved-markdown-preview">{value}</div>,
+}))
+
+vi.mock('../sqlite-file-preview', () => ({
+  default: ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="resolved-sqlite-preview">{downloadUrl}</div>,
+}))
+
+vi.mock('../pdf-file-preview', () => ({
+  default: ({ downloadUrl }: { downloadUrl: string }) => <div data-testid="resolved-pdf-preview">{downloadUrl}</div>,
+}))
+
+vi.mock('../unsupported-file-download', () => ({
+  default: ({ name }: { name: string }) => <div data-testid="unsupported-preview">{name}</div>,
+}))
+
+vi.mock('../../hooks/use-file-type-info', () => ({
+  useFileTypeInfo: () => mocks.fileTypeInfo,
+}))
+
+vi.mock('../../hooks/use-fetch-text-content', () => ({
+  useFetchTextContent: (downloadUrl?: string) => {
+    mocks.fetchArgs.push(downloadUrl)
+    return mocks.fetchState
+  },
+}))
+
+vi.mock('../../utils/file-utils', () => ({
+  getFileLanguage: (name: string) => mocks.getFileLanguage(name),
+}))
+describe('ReadOnlyFilePreview', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.dynamicIndex = 0
+    mocks.fileTypeInfo = {
+      isMarkdown: false,
+      isCodeOrText: false,
+      isImage: false,
+      isVideo: false,
+      isPdf: false,
+      isSQLite: false,
+      isEditable: false,
+      isMediaFile: false,
+      isPreviewable: false,
+    }
+    mocks.fetchState = {
+      data: undefined,
+      isLoading: false,
+    }
+    mocks.dynamicLoaders.length = 0
+    mocks.dynamicImporters.length = 0
+    mocks.fetchArgs.length = 0
+  })
+
+  it('should render the unsupported download state for non-previewable files', () => {
+    render(<ReadOnlyFilePreview downloadUrl="https://example.com/file.bin" fileName="file.bin" />)
+
+    expect(screen.getByTestId('unsupported-preview')).toHaveTextContent('file.bin')
+  })
+
+  it('should show a loading state while text content is being fetched', () => {
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isCodeOrText: true,
+      isEditable: true,
+      isPreviewable: true,
+    }
+    mocks.fetchState = {
+      data: undefined,
+      isLoading: true,
+    }
+
+    render(<ReadOnlyFilePreview downloadUrl="https://example.com/file.ts" fileName="file.ts" />)
+
+    expect(screen.getByRole('status')).toBeInTheDocument()
+  })
+
+  it('should render markdown, code, media, sqlite, and pdf previews for supported files', () => {
+    const { rerender } = render(<ReadOnlyFilePreview downloadUrl="https://example.com/file.bin" fileName="file.bin" />)
+
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isMarkdown: true,
+      isEditable: true,
+      isPreviewable: true,
+    }
+    mocks.fetchState = {
+      data: '# Skill',
+      isLoading: false,
+    }
+    rerender(<ReadOnlyFilePreview downloadUrl="https://example.com/guide.md" fileName="guide.md" />)
+    expect(screen.getByTestId('markdown-preview')).toHaveTextContent('# Skill')
+    expect(mocks.fetchArgs.at(-1)).toBe('https://example.com/guide.md')
+
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isMarkdown: false,
+      isCodeOrText: true,
+      isEditable: true,
+      isPreviewable: true,
+    }
+    mocks.fetchState = {
+      data: 'const a = 1',
+      isLoading: false,
+    }
+    rerender(<ReadOnlyFilePreview downloadUrl="https://example.com/file.ts" fileName="file.ts" />)
+    expect(screen.getByTestId('code-preview')).toHaveTextContent('typescript:const a = 1')
+    expect(mocks.getFileLanguage).toHaveBeenCalledWith('file.ts')
+    expect(mocks.fetchArgs.at(-1)).toBe('https://example.com/file.ts')
+
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isCodeOrText: false,
+      isImage: true,
+      isEditable: false,
+      isPreviewable: true,
+    }
+    rerender(<ReadOnlyFilePreview downloadUrl="https://example.com/file.png" fileName="file.png" />)
+    expect(screen.getByTestId('media-preview')).toHaveTextContent('image:https://example.com/file.png')
+    expect(mocks.fetchArgs.at(-1)).toBeUndefined()
+
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isImage: false,
+      isSQLite: true,
+      isPreviewable: true,
+    }
+    rerender(<ReadOnlyFilePreview downloadUrl="https://example.com/file.db" fileName="file.db" />)
+    expect(screen.getByTestId('sqlite-preview')).toHaveTextContent('https://example.com/file.db')
+
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isSQLite: false,
+      isPdf: true,
+      isPreviewable: true,
+    }
+    rerender(<ReadOnlyFilePreview downloadUrl="https://example.com/file.pdf" fileName="file.pdf" />)
+    expect(screen.getByTestId('pdf-preview')).toHaveTextContent('https://example.com/file.pdf')
+  })
+
+  it('should render a video preview when the file type info marks it as video', () => {
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isVideo: true,
+      isPreviewable: true,
+    }
+
+    render(<ReadOnlyFilePreview downloadUrl="https://example.com/file.mp4" fileName="file.mp4" />)
+
+    expect(screen.getByTestId('media-preview')).toHaveTextContent('video:https://example.com/file.mp4')
+  })
+
+  it('should render the unsupported fallback when a previewable file has no dedicated renderer', () => {
+    mocks.fileTypeInfo = {
+      ...mocks.fileTypeInfo,
+      isPreviewable: true,
+    }
+
+    render(<ReadOnlyFilePreview downloadUrl="https://example.com/file.custom" fileName="file.custom" fileSize={null} />)
+
+    expect(screen.getByTestId('unsupported-preview')).toHaveTextContent('file.custom')
+  })
+
+  it('should expose loading placeholders for all dynamic preview modules', async () => {
+    vi.resetModules()
+    mocks.dynamicLoaders.length = 0
+    mocks.dynamicImporters.length = 0
+
+    const readOnlyFilePreviewModule = await import('../read-only-file-preview')
+    const FreshReadOnlyFilePreview = readOnlyFilePreviewModule.default
+
+    render(<FreshReadOnlyFilePreview downloadUrl="https://example.com/file.bin" fileName="file.bin" />)
+
+    expect(mocks.dynamicLoaders).toHaveLength(4)
+    expect(mocks.dynamicImporters).toHaveLength(4)
+    mocks.dynamicLoaders.forEach((renderLoader) => {
+      const { unmount } = render(<>{renderLoader()}</>)
+      expect(screen.getByRole('status')).toBeInTheDocument()
+      unmount()
+    })
+    for (const loadModule of mocks.dynamicImporters)
+      await expect(loadModule()).resolves.toBeTruthy()
+    expect(Loading).toBeDefined()
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/__tests__/read-only-markdown-preview.spec.tsx b/web/app/components/workflow/skill/viewer/__tests__/read-only-markdown-preview.spec.tsx
new file mode 100644
index 00000000000..79ae9cabc05
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/__tests__/read-only-markdown-preview.spec.tsx
@@ -0,0 +1,37 @@
+import { render } from '@testing-library/react'
+
+import ReadOnlyMarkdownPreview from '../read-only-markdown-preview'
+
+const mocks = vi.hoisted(() => ({
+  editorProps: [] as Array<Record<string, unknown>>,
+}))
+
+vi.mock('../../editor/markdown-file-editor', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.editorProps.push(props)
+    return <div data-testid="markdown-editor" />
+  },
+}))
+
+describe('ReadOnlyMarkdownPreview', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.editorProps.length = 0
+  })
+
+  it('should render the markdown editor in read only mode', () => {
+    render(<ReadOnlyMarkdownPreview value="# Skill" />)
+
+    expect(mocks.editorProps[0]).toMatchObject({
+      value: '# Skill',
+      readOnly: true,
+    })
+    expect(typeof mocks.editorProps[0].onChange).toBe('function')
+  })
+
+  it('should provide a no-op change handler for the read-only editor', () => {
+    render(<ReadOnlyMarkdownPreview value="# Skill" />)
+
+    expect(() => (mocks.editorProps[0].onChange as () => void)()).not.toThrow()
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/__tests__/unsupported-file-download.spec.tsx b/web/app/components/workflow/skill/viewer/__tests__/unsupported-file-download.spec.tsx
new file mode 100644
index 00000000000..ece88df3dde
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/__tests__/unsupported-file-download.spec.tsx
@@ -0,0 +1,46 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+
+import UnsupportedFileDownload from '../unsupported-file-download'
+
+const mocks = vi.hoisted(() => ({
+  downloadUrl: vi.fn(),
+}))
+
+vi.mock('@/utils/download', () => ({
+  downloadUrl: (args: { url: string, fileName: string }) => mocks.downloadUrl(args),
+}))
+
+describe('UnsupportedFileDownload', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('should render file metadata and trigger a download when a url is available', () => {
+    render(
+      <UnsupportedFileDownload
+        name="archive.zip"
+        size={1024}
+        downloadUrl="https://example.com/archive.zip"
+      />,
+    )
+
+    fireEvent.click(screen.getByRole('button', { name: 'common.operation.download' }))
+
+    expect(screen.getByText('archive.zip')).toBeInTheDocument()
+    expect(screen.getByText('1.00 KB')).toBeInTheDocument()
+    expect(mocks.downloadUrl).toHaveBeenCalledWith({
+      url: 'https://example.com/archive.zip',
+      fileName: 'archive.zip',
+    })
+  })
+
+  it('should disable the download action when no url is available', () => {
+    render(<UnsupportedFileDownload name="archive.zip" />)
+
+    const button = screen.getByRole('button', { name: 'common.operation.download' })
+    expect(button).toBeDisabled()
+
+    fireEvent.click(button)
+    expect(mocks.downloadUrl).not.toHaveBeenCalled()
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/constants.spec.ts b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/constants.spec.ts
new file mode 100644
index 00000000000..e59412cc9ff
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/constants.spec.ts
@@ -0,0 +1,7 @@
+import { PREVIEW_ROW_LIMIT } from '../constants'
+
+describe('sqlite preview constants', () => {
+  it('should expose the preview row limit', () => {
+    expect(PREVIEW_ROW_LIMIT).toBe(1000)
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/data-table.spec.tsx b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/data-table.spec.tsx
new file mode 100644
index 00000000000..3019a4de3cf
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/data-table.spec.tsx
@@ -0,0 +1,116 @@
+import type { RefObject } from 'react'
+import { render, screen } from '@testing-library/react'
+import DataTable from '../data-table'
+
+const mocks = vi.hoisted(() => ({
+  lastOptions: null as null | {
+    getScrollElement: () => HTMLDivElement | null
+    estimateSize: () => number
+  },
+  virtualRows: [
+    { index: 0, start: 10, end: 42 },
+    { index: 1, start: 42, end: 74 },
+  ],
+  totalSize: 100,
+}))
+
+vi.mock('@tanstack/react-virtual', () => ({
+  useVirtualizer: (options: typeof mocks.lastOptions) => {
+    mocks.lastOptions = options
+    options?.getScrollElement()
+    options?.estimateSize()
+    return {
+      getVirtualItems: () => mocks.virtualRows,
+      getTotalSize: () => mocks.totalSize,
+    }
+  },
+}))
+
+vi.mock('react-i18next', () => ({
+  useTranslation: () => ({
+    t: (key: string, options?: Record<string, unknown>) => `${key}${options ? `:${JSON.stringify(options)}` : ''}`,
+  }),
+}))
+const createScrollRef = () => ({ current: null }) as RefObject<HTMLDivElement | null>
+
+describe('DataTable', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.lastOptions = null
+    mocks.virtualRows = [
+      { index: 0, start: 10, end: 42 },
+      { index: 1, start: 42, end: 74 },
+    ]
+    mocks.totalSize = 100
+  })
+
+  it('should render virtualized rows, formatted values, and truncation footer', () => {
+    const longText = 'x'.repeat(130)
+
+    const { container } = render(
+      <DataTable
+        columns={['id', 'empty', 'blob', 'big', 'description']}
+        values={[
+          [1, null, new Uint8Array([1, 2]), 3n, longText],
+          [2, 'value', new Uint8Array([3]), 4n, 'short'],
+        ]}
+        scrollRef={createScrollRef()}
+        isTruncated
+      />,
+    )
+
+    expect(screen.getByText('id')).toBeInTheDocument()
+    expect(screen.getByText('1')).toBeInTheDocument()
+    expect(screen.getByText('skillSidebar.sqlitePreview.nullValue')).toBeInTheDocument()
+    expect(screen.getByText('skillSidebar.sqlitePreview.blobValue:{"size":2}')).toBeInTheDocument()
+    expect(screen.getByText(`${'x'.repeat(120)}…`)).toBeInTheDocument()
+    expect(screen.getByText('skillSidebar.sqlitePreview.rowsTruncated:{"limit":2}')).toBeInTheDocument()
+    expect(container.querySelectorAll('tr[aria-hidden="true"]')).toHaveLength(2)
+    expect(mocks.lastOptions?.estimateSize()).toBe(32)
+    expect(mocks.lastOptions?.getScrollElement()).toBeNull()
+  })
+
+  it('should fall back to the row index as a key when no key column exists', () => {
+    render(
+      <DataTable
+        columns={['name']}
+        values={[['Ada'], ['Grace']]}
+        scrollRef={createScrollRef()}
+      />,
+    )
+
+    expect(screen.getByText('Ada')).toBeInTheDocument()
+    expect(screen.getByText('Grace')).toBeInTheDocument()
+  })
+
+  it('should fall back to the virtual row index when the key column value is null', () => {
+    mocks.virtualRows = [{ index: 0, start: 0, end: 32 }]
+    mocks.totalSize = 32
+
+    render(
+      <DataTable
+        columns={['id', 'name']}
+        values={[[null, 'Ada']]}
+        scrollRef={createScrollRef()}
+      />,
+    )
+
+    expect(screen.getByText('Ada')).toBeInTheDocument()
+  })
+
+  it('should skip spacer rows when the virtualizer has no visible rows', () => {
+    mocks.virtualRows = []
+    mocks.totalSize = 0
+
+    const { container } = render(
+      <DataTable
+        columns={['name']}
+        values={[]}
+        scrollRef={createScrollRef()}
+      />,
+    )
+
+    expect(container.querySelectorAll('tr[aria-hidden="true"]')).toHaveLength(0)
+    expect(screen.getByText('name')).toBeInTheDocument()
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/index.spec.tsx b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/index.spec.tsx
new file mode 100644
index 00000000000..1d4ee81194c
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/index.spec.tsx
@@ -0,0 +1,138 @@
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+
+import SQLiteFilePreview from '../index'
+
+const mocks = vi.hoisted(() => ({
+  databaseState: {
+    tables: [] as string[],
+    isLoading: false,
+    error: null as Error | null,
+    queryTable: vi.fn(),
+  },
+  tableState: {
+    data: null as null | { columns: string[], values: unknown[][] },
+    isLoading: false,
+    error: null as Error | null,
+  },
+  selectorProps: [] as Array<Record<string, unknown>>,
+  panelProps: [] as Array<Record<string, unknown>>,
+}))
+
+vi.mock('../../../hooks/use-sqlite-database', () => ({
+  useSQLiteDatabase: () => mocks.databaseState,
+}))
+
+vi.mock('../use-sqlite-table', () => ({
+  useSQLiteTable: (args: unknown) => {
+    mocks.selectorProps.push({ hookArgs: args })
+    return mocks.tableState
+  },
+}))
+
+vi.mock('../table-selector', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.selectorProps.push(props)
+    return (
+      <button type="button" onClick={() => (props.onTableChange as (value: string) => void)('events')}>
+        change-table
+      </button>
+    )
+  },
+}))
+
+vi.mock('../table-panel', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.panelProps.push(props)
+    return <div data-testid="sqlite-table-panel" />
+  },
+}))
+
+describe('SQLiteFilePreview', () => {
+  const getHookInvocations = () => {
+    return mocks.selectorProps.filter(item => Object.hasOwn(item, 'hookArgs'))
+  }
+
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.selectorProps.length = 0
+    mocks.panelProps.length = 0
+    mocks.databaseState = {
+      tables: [],
+      isLoading: false,
+      error: null,
+      queryTable: vi.fn(),
+    }
+    mocks.tableState = {
+      data: null,
+      isLoading: false,
+      error: null,
+    }
+  })
+
+  it('should render the unavailable state when no url is provided', () => {
+    render(<SQLiteFilePreview downloadUrl="" />)
+
+    expect(screen.getByText('workflow.skillEditor.previewUnavailable')).toBeInTheDocument()
+  })
+
+  it('should render the loading state from the database hook', () => {
+    mocks.databaseState.isLoading = true
+    render(<SQLiteFilePreview downloadUrl="https://example.com/demo.db?state=loading" />)
+
+    expect(screen.getByRole('status')).toBeInTheDocument()
+  })
+
+  it('should render the error state from the database hook', () => {
+    mocks.databaseState.error = new Error('boom')
+
+    render(<SQLiteFilePreview downloadUrl="https://example.com/demo.db?state=error" />)
+
+    expect(screen.getByText('workflow.skillSidebar.sqlitePreview.loadError')).toBeInTheDocument()
+  })
+
+  it('should render the empty state when the database has no tables', () => {
+    render(<SQLiteFilePreview downloadUrl="https://example.com/demo.db?state=empty" />)
+
+    expect(screen.getByText('workflow.skillSidebar.sqlitePreview.emptyTables')).toBeInTheDocument()
+  })
+
+  it('should render selector and panel props when tables are available', () => {
+    mocks.databaseState.tables = ['users', 'events']
+    mocks.tableState.data = {
+      columns: ['id'],
+      values: Array.from({ length: 1000 }, (_, index) => [index + 1]),
+    }
+
+    render(<SQLiteFilePreview downloadUrl="https://example.com/demo.db" />)
+
+    expect(screen.getByTestId('sqlite-table-panel')).toBeInTheDocument()
+    expect(mocks.selectorProps.find(item => Object.hasOwn(item, 'tables'))).toMatchObject({
+      tables: ['users', 'events'],
+      selectedTable: 'users',
+      isLoading: false,
+    })
+    expect(mocks.panelProps[0]).toMatchObject({
+      data: mocks.tableState.data,
+      isLoading: false,
+      error: null,
+      isTruncated: true,
+    })
+  })
+
+  it('should update the selected table when the selector changes', () => {
+    mocks.databaseState.tables = ['users', 'events']
+
+    render(<SQLiteFilePreview downloadUrl="https://example.com/demo.db" />)
+
+    fireEvent.click(screen.getByRole('button', { name: 'change-table' }))
+
+    return waitFor(() => {
+      expect(getHookInvocations().at(-1)).toMatchObject({
+        hookArgs: {
+          selectedTable: 'events',
+          queryTable: mocks.databaseState.queryTable,
+        },
+      })
+    })
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/table-panel.spec.tsx b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/table-panel.spec.tsx
new file mode 100644
index 00000000000..63ec190f7dc
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/table-panel.spec.tsx
@@ -0,0 +1,87 @@
+import type { RefObject } from 'react'
+import { render, screen } from '@testing-library/react'
+import TablePanel from '../table-panel'
+
+const mocks = vi.hoisted(() => ({
+  dataTableProps: [] as Array<Record<string, unknown>>,
+}))
+
+vi.mock('../data-table', () => ({
+  default: (props: Record<string, unknown>) => {
+    mocks.dataTableProps.push(props)
+    return <div data-testid="sqlite-data-table" />
+  },
+}))
+const createScrollRef = () => ({ current: null }) as RefObject<HTMLDivElement | null>
+
+describe('TablePanel', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.dataTableProps.length = 0
+  })
+
+  it('should render a loading state', () => {
+    render(
+      <TablePanel
+        data={null}
+        isLoading
+        error={null}
+        scrollRef={createScrollRef()}
+      />,
+    )
+
+    expect(screen.getByRole('status')).toBeInTheDocument()
+  })
+
+  it('should render an error state', () => {
+    render(
+      <TablePanel
+        data={null}
+        isLoading={false}
+        error={new Error('boom')}
+        scrollRef={createScrollRef()}
+      />,
+    )
+
+    expect(screen.getByText('workflow.skillSidebar.sqlitePreview.loadError')).toBeInTheDocument()
+  })
+
+  it('should render the data table when rows are available', () => {
+    const scrollRef = createScrollRef()
+    const data = {
+      columns: ['id'],
+      values: [[1]],
+    }
+
+    render(
+      <TablePanel
+        data={data}
+        isLoading={false}
+        error={null}
+        scrollRef={scrollRef}
+        isTruncated
+      />,
+    )
+
+    expect(screen.getByTestId('sqlite-data-table')).toBeInTheDocument()
+    expect(mocks.dataTableProps[0]).toMatchObject({
+      columns: ['id'],
+      values: [[1]],
+      scrollRef,
+      isTruncated: true,
+    })
+  })
+
+  it('should render an empty state when no rows are available', () => {
+    render(
+      <TablePanel
+        data={null}
+        isLoading={false}
+        error={null}
+        scrollRef={createScrollRef()}
+      />,
+    )
+
+    expect(screen.getByText('workflow.skillSidebar.sqlitePreview.emptyRows')).toBeInTheDocument()
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/table-selector.spec.tsx b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/table-selector.spec.tsx
new file mode 100644
index 00000000000..8543e722751
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/table-selector.spec.tsx
@@ -0,0 +1,68 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+
+import TableSelector from '../table-selector'
+
+vi.mock('@/app/components/base/portal-to-follow-elem', () => ({
+  PortalToFollowElem: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+  PortalToFollowElemTrigger: ({ children }: { children: React.ReactNode }) => <>{children}</>,
+  PortalToFollowElemContent: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+}))
+
+describe('TableSelector', () => {
+  it('should render a compact label when only one table is available', () => {
+    render(
+      <TableSelector
+        tables={['users']}
+        selectedTable=""
+        onTableChange={vi.fn()}
+      />,
+    )
+
+    expect(screen.getByText('workflow.skillSidebar.sqlitePreview.selectTable')).toBeInTheDocument()
+    expect(screen.queryByRole('button')).not.toBeInTheDocument()
+  })
+
+  it('should render placeholder styling for multi-table selectors without a selection', () => {
+    render(
+      <TableSelector
+        tables={['users', 'events']}
+        selectedTable=""
+        onTableChange={vi.fn()}
+      />,
+    )
+
+    const trigger = screen.getAllByRole('button', { name: /workflow\.skillSidebar\.sqlitePreview\.selectTable/i })[0]
+    expect(trigger).toHaveClass('cursor-pointer')
+    expect(screen.getByText('workflow.skillSidebar.sqlitePreview.selectTable')).toHaveClass('text-text-tertiary')
+  })
+
+  it('should allow selecting a different table', () => {
+    const onTableChange = vi.fn()
+
+    render(
+      <TableSelector
+        tables={['users', 'events']}
+        selectedTable="users"
+        onTableChange={onTableChange}
+      />,
+    )
+
+    fireEvent.click(screen.getAllByRole('button', { name: /users/i })[0])
+    fireEvent.click(screen.getByRole('button', { name: /events/i }))
+
+    expect(onTableChange).toHaveBeenCalledWith('events')
+  })
+
+  it('should disable the trigger while loading', () => {
+    render(
+      <TableSelector
+        tables={['users', 'events']}
+        selectedTable="users"
+        isLoading
+        onTableChange={vi.fn()}
+      />,
+    )
+
+    expect(screen.getAllByRole('button', { name: /users/i })[0]).toBeDisabled()
+  })
+})
diff --git a/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/use-sqlite-table.spec.tsx b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/use-sqlite-table.spec.tsx
new file mode 100644
index 00000000000..68119157dad
--- /dev/null
+++ b/web/app/components/workflow/skill/viewer/sqlite-file-preview/__tests__/use-sqlite-table.spec.tsx
@@ -0,0 +1,128 @@
+import { renderHook, waitFor } from '@testing-library/react'
+import { useSQLiteTable } from '../use-sqlite-table'
+
+describe('useSQLiteTable', () => {
+  it('should reset when no table is selected', () => {
+    const queryTable = vi.fn()
+
+    const { result } = renderHook(() => useSQLiteTable({
+      selectedTable: '',
+      queryTable,
+    }))
+
+    expect(queryTable).not.toHaveBeenCalled()
+    expect(result.current).toEqual({
+      data: null,
+      isLoading: false,
+      error: null,
+    })
+  })
+
+  it('should load the selected table with the preview row limit', async () => {
+    const queryTable = vi.fn().mockResolvedValue({
+      columns: ['id'],
+      values: [[1]],
+    })
+
+    const { result } = renderHook(() => useSQLiteTable({
+      selectedTable: 'users',
+      queryTable,
+    }))
+
+    expect(result.current.isLoading).toBe(true)
+    await waitFor(() => expect(result.current.data).toEqual({
+      columns: ['id'],
+      values: [[1]],
+    }))
+
+    expect(queryTable).toHaveBeenCalledWith('users', 1000)
+    expect(result.current.error).toBeNull()
+  })
+
+  it('should surface query errors', async () => {
+    const queryTable = vi.fn().mockRejectedValue(new Error('boom'))
+
+    const { result } = renderHook(() => useSQLiteTable({
+      selectedTable: 'users',
+      queryTable,
+    }))
+
+    await waitFor(() => expect(result.current.error?.message).toBe('boom'))
+    expect(result.current.data).toBeNull()
+    expect(result.current.isLoading).toBe(false)
+  })
+
+  it('should wrap non-error rejections in an Error instance', async () => {
+    const queryTable = vi.fn().mockRejectedValue('boom')
+
+    const { result } = renderHook(() => useSQLiteTable({
+      selectedTable: 'users',
+      queryTable,
+    }))
+
+    await waitFor(() => expect(result.current.error?.message).toBe('boom'))
+    expect(result.current.error).toBeInstanceOf(Error)
+  })
+
+  it('should ignore stale async results after the table changes', async () => {
+    let resolveFirst!: (value: { columns: string[], values: number[][] }) => void
+    const queryTable = vi
+      .fn()
+      .mockImplementationOnce(() => new Promise((resolve) => {
+        resolveFirst = resolve
+      }))
+      .mockResolvedValueOnce({
+        columns: ['id'],
+        values: [[2]],
+      })
+
+    const { result, rerender } = renderHook(
+      ({ selectedTable }) => useSQLiteTable({
+        selectedTable,
+        queryTable,
+      }),
+      {
+        initialProps: {
+          selectedTable: 'users',
+        },
+      },
+    )
+
+    rerender({ selectedTable: 'events' })
+    resolveFirst({
+      columns: ['id'],
+      values: [[1]],
+    })
+
+    await waitFor(() => expect(result.current.data).toEqual({
+      columns: ['id'],
+      values: [[2]],
+    }))
+  })
+
+  it('should ignore rejected requests after the selection resets', async () => {
+    let rejectFirst!: (reason?: unknown) => void
+    const queryTable = vi.fn().mockImplementation(() => new Promise((_, reject) => {
+      rejectFirst = reject
+    }))
+
+    const { result, rerender } = renderHook(
+      ({ selectedTable }) => useSQLiteTable({
+        selectedTable,
+        queryTable,
+      }),
+      {
+        initialProps: {
+          selectedTable: 'users',
+        },
+      },
+    )
+
+    rerender({ selectedTable: '' })
+    rejectFirst(new Error('late failure'))
+
+    await waitFor(() => expect(result.current.isLoading).toBe(false))
+    expect(result.current.error).toBeNull()
+    expect(result.current.data).toBeNull()
+  })
+})