Pin all Python dependency versions in requirements.txt

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

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

backend/requirements.txt

@@ -1,33 +1,33 @@
 # Web Framework (Async)
-quart
-quart-cors
-hypercorn
-werkzeug
+quart==0.20.0
+quart-cors==0.8.0
+hypercorn==0.17.3
+werkzeug==3.1.3
 
 # Database (Async)
-motor
-pymongo
+motor==3.7.1
+pymongo==4.14.1
 
 # Authentication & Security
-bcrypt
-PyJWT
-msal
+bcrypt==4.0.1
+PyJWT==2.8.0
+msal==1.24.1
 
 # AI & LLM Services
-google-genai
-openai
-llama-cloud-services
+google-genai==1.52.0
+openai==1.99.5
+llama-cloud-services==0.6.62
 
 # WebSocket & Real-time
-python-socketio
+python-socketio==5.13.0
 
 # HTTP Clients
-httpx
-requests
+httpx==0.28.1
+requests==2.31.0
 
 # Data Validation & Processing
-pydantic
-pillow
+pydantic==2.11.7
+pillow==11.3.0
 
 # Configuration & Utilities
-python-dotenv
+python-dotenv==1.1.1