Fix upload timeout issue: increase Gunicorn worker timeout to 300s

- Increased timeout from 60s to 300s (5 minutes) for large file uploads
- Added max_requests, max_requests_jitter, and worker_connections settings
- Removed limits on request line and field sizes to handle large uploads
- Also updated Nginx configuration with optimized timeout settings for /upload endpoint

This resolves the 502 Bad Gateway errors that were occurring during large file uploads due to worker timeouts.

gunicorn.conf.py

@@ -1,10 +1,16 @@
 bind = "0.0.0.0:8000"
 workers = 2  # Tune based on available CPU cores
 worker_class = "uvicorn.workers.UvicornWorker"
-timeout = 60
+timeout = 300  # Increased from 60 to 300 seconds (5 minutes)
 keepalive = 30
 loglevel = "info"
 accesslog = "-"
 errorlog = "-"
 proxy_allow_ips = "*"
+max_requests = 1000
+max_requests_jitter = 50
+worker_connections = 1000
+limit_request_line = 0  # No limit on request line size
+limit_request_field_size = 0  # No limit on field size
+limit_request_fields = 100  # Limit number of header fields