Fix HuggingFace cache permission denied error

- Create /.cache directory with proper permissions
- Set HF_HOME environment variable to writable cache path
- Resolves runtime permission error during model download

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

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

Dockerfile

@@ -46,13 +46,15 @@ COPY data ./data
 # Copy the built frontend from the builder stage
 COPY --from=builder /app/ui/claimcheck-ui/dist ./static
 
-# Create necessary directories
-RUN mkdir -p kb/index data/audio
+# Create necessary directories and fix cache permissions
+RUN mkdir -p kb/index data/audio /.cache && \
+    chmod 777 /.cache
 
 # Set environment variables for production
 ENV PYTHONUNBUFFERED=1
 ENV HOST=0.0.0.0
 ENV PORT=7860
+ENV HF_HOME=/.cache
 
 # Expose the port for Hugging Face Spaces
 EXPOSE 7860