fix: add missing Optional import

fix: repair corrupted requirements.txt

chore: async modernization and BYOK support (without secrets)

Perf: Add internal heartbeat to prevent idle sleep

Fix: Hardened key retrieval and Appwrite project fallback

UI: Add minimal API landing page to root

Fix: Correct encoding and add missing dependencies

Fix: Add missing langchain-anthropic dependency

Production Hardening: Health check, Bug fixes, and Key fallback

Debug: Simplify boot and set PYTHONPATH

Clean Deployment v2