Add scripts/cfw_install_jb_post.sh — an idempotent SSH-based finalizer to complete JB bootstrap on a normally-booted vphone (creates /var/jb symlink, fixes ownership, runs prep_bootstrap, creates markers, installs Sileo, and runs apt; requires sshpass). Add Makefile help, .PHONY and target cfw_install_jb_finalize to invoke the script. Remove host-side IPA signing/installing and related UI: delete VPhoneSigner, VPhoneIPAInstaller, VPhoneMenuInstall and remove signer/ipaInstaller fields and menu items/callbacks from the vphone-cli UI (also removed the DevMode enable WIP flow). Misc: minor table/formatting tweaks in AGENTS.md and research docs.