Add OAuth dependencies to fix Gradio OAuth initialization error

- Update gradio dependency to gradio[oauth]>=4.0.0 to include OAuth extras
- Add explicit itsdangerous>=2.0.0 and starlette>=0.27.0 dependencies
- Fixes ImportError: Cannot initialize OAuth due to missing itsdangerous module
- Enables proper HuggingFace OAuth authentication in Spaces deployment

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

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

requirements-hf.txt

@@ -2,7 +2,7 @@
 # Optimized for deployment
 
 # Core dependencies
-gradio>=4.0.0
+gradio[oauth]>=4.0.0
 torch>=2.0.0
 transformers>=4.53.0
 diffusers>=0.30.0
@@ -23,6 +23,10 @@ mcp>=1.0.0
 # HuggingFace integration
 huggingface-hub>=0.20.0
 
+# OAuth and session management
+itsdangerous>=2.0.0
+starlette>=0.27.0
+
 # Utilities
 pillow>=10.0.0
 numpy>=1.24.0