Restructure into full project layout

backend/requirements.txt

@@ -0,0 +1,15 @@
+fastapi==0.111.0
+uvicorn[standard]==0.29.0
+sqlalchemy[asyncio]==2.0.29
+asyncpg==0.29.0
+alembic==1.13.1
+pydantic[email]==2.7.1
+pydantic-settings==2.2.1
+python-jose[cryptography]==3.3.0
+passlib[bcrypt]==1.7.4
+python-multipart==0.0.9
+httpx==0.27.0
+anthropic==0.25.0
+redis[hiredis]==5.0.4
+tenacity==8.2.3
+chardet==5.2.0