feat: enterprise otel exporter (#33138)

Co-authored-by: QuantumGhost <obelisk.reg+git@gmail.com>
Co-authored-by: Yunlu Wen <yunlu.wen@dify.ai>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/enterprise/telemetry/contracts.py

@@ -0,0 +1,73 @@
+"""Telemetry gateway contracts and data structures.
+
+This module defines the envelope format for telemetry events and the routing
+configuration that determines how each event type is processed.
+"""
+
+from __future__ import annotations
+
+from enum import StrEnum
+from typing import Any
+
+from pydantic import BaseModel, ConfigDict
+
+
+class TelemetryCase(StrEnum):
+    """Enumeration of all known telemetry event cases."""
+
+    WORKFLOW_RUN = "workflow_run"
+    NODE_EXECUTION = "node_execution"
+    DRAFT_NODE_EXECUTION = "draft_node_execution"
+    MESSAGE_RUN = "message_run"
+    TOOL_EXECUTION = "tool_execution"
+    MODERATION_CHECK = "moderation_check"
+    SUGGESTED_QUESTION = "suggested_question"
+    DATASET_RETRIEVAL = "dataset_retrieval"
+    GENERATE_NAME = "generate_name"
+    PROMPT_GENERATION = "prompt_generation"
+    APP_CREATED = "app_created"
+    APP_UPDATED = "app_updated"
+    APP_DELETED = "app_deleted"
+    FEEDBACK_CREATED = "feedback_created"
+
+
+class SignalType(StrEnum):
+    """Signal routing type for telemetry cases."""
+
+    TRACE = "trace"
+    METRIC_LOG = "metric_log"
+
+
+class CaseRoute(BaseModel):
+    """Routing configuration for a telemetry case.
+
+    Attributes:
+        signal_type: The type of signal (trace or metric_log).
+        ce_eligible: Whether this case is eligible for community edition tracing.
+    """
+
+    signal_type: SignalType
+    ce_eligible: bool
+
+
+class TelemetryEnvelope(BaseModel):
+    """Envelope for telemetry events.
+
+    Attributes:
+        case: The telemetry case type.
+        tenant_id: The tenant identifier.
+        event_id: Unique event identifier for deduplication.
+        payload: The main event payload (inline for small payloads,
+            empty when offloaded to storage via ``payload_ref``).
+        metadata: Optional metadata dictionary.  When the gateway
+            offloads a large payload to object storage, this contains
+            ``{"payload_ref": "<storage_key>"}``.
+    """
+
+    model_config = ConfigDict(extra="forbid", use_enum_values=False)
+
+    case: TelemetryCase
+    tenant_id: str
+    event_id: str
+    payload: dict[str, Any]
+    metadata: dict[str, Any] | None = None