Fix syntax error in playground.py

Fix pydantic version constraint for composio compat

Refactor: use Composio Core SDK as backend engine

Implement real OAuth flow with token exchange + vault credential injection in tool executor

Complete frontend rebuild: 11 pages, professional composio-level design, connections/playground pages, fixed tailwind config

Seed auth configs from JSON cache

Fix health endpoint routing order

Add dynamic auth configs, connect page, Next.js frontend

fix: add newline before email-validator in requirements.txt

fix: add email-validator dependency

fix: use backend. prefix for all internal imports

fix: use backend. prefix for imports in registry.py

fix: pin bcrypt==4.0.1 for passlib compatibility

fix: rename metadata column (reserved in SQLAlchemy)

feat: full platform with dynamic Composio sync, local DB cache, React UI