refactor: Remove deprecated INTERNAL_API_PORT (ultrathin monolith cleanup)

Architecture cleanup after migration to ultrathin monolith:

- Remove INTERNAL_API_PORT from .env files (was port 8002)
- Clean up bot_main.py: remove uvicorn, Thread, run_internal_api()
- Update validate.md to check /api/telegram/health instead of port 8002
- Add deprecation notices to old Windows deployment docs
- Update docs/telegram/README.md with architecture note

The Telegram internal API is now served at /api/telegram/internal/*
on the main backend port (8000/8001) instead of separate port 8002.

Also includes: menu updates, ServerLogsView improvements, script fixes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/.env.test.example

@@ -144,7 +144,7 @@ TELEGRAM_BOT_TOKEN=8483383555:AAGNY1z6WiBkvVfy1ZV_gM_JnAqW4q4MlEY
 BACKEND_URL=http://localhost:8000
 
 # Internal API port (bot's internal API for backend callbacks)
-INTERNAL_API_PORT=8002
+# INTERNAL_API_PORT=8002  # DEPRECATED: Now served via main app at /api/telegram/internal/*
 
 # Enable internal API documentation (development only)
 ENABLE_DOCS=false