Bind nginx load balancer to all interfaces (0.0.0.0) (#11) (#337)

Change the nginx listen directive from `listen 8501` to
`listen 0.0.0.0:8501` so the load balancer explicitly accepts
connections on all network interfaces, not just the default.

https://claude.ai/code/session_01721rHYJhSZfJnnUpWHXbVs

Co-authored-by: Claude <[email protected]>

Author: t0mdavid-m

Dockerfile

@@ -200,7 +200,7 @@ if [ "$SERVER_COUNT" -gt 1 ]; then\n\
 \n\
     # Write nginx config\n\
     mkdir -p /etc/nginx\n\
-    echo -e "worker_processes auto;\\npid /run/nginx.pid;\\n\\nevents {\\n    worker_connections 1024;\\n}\\n\\nhttp {\\n    client_max_body_size 0;\\n\\n    map \\$cookie_stroute \\$route_key {\\n        \\x22\\x22      \\$request_id;\\n        default \\$cookie_stroute;\\n    }\\n\\n    upstream streamlit_backend {\\n        hash \\$route_key consistent;\\n${UPSTREAM_SERVERS}    }\\n\\n    map \\$http_upgrade \\$connection_upgrade {\\n        default upgrade;\\n        \\x27\\x27 close;\\n    }\\n\\n    server {\\n        listen 8501;\\n\\n        location / {\\n            proxy_pass http://streamlit_backend;\\n            proxy_http_version 1.1;\\n            proxy_set_header Upgrade \\$http_upgrade;\\n            proxy_set_header Connection \\$connection_upgrade;\\n            proxy_set_header Host \\$host;\\n            proxy_set_header X-Real-IP \\$remote_addr;\\n            proxy_set_header X-Forwarded-For \\$proxy_add_x_forwarded_for;\\n            proxy_set_header X-Forwarded-Proto \\$scheme;\\n            proxy_read_timeout 86400;\\n            proxy_send_timeout 86400;\\n            proxy_buffering off;\\n            add_header Set-Cookie \\x22stroute=\\$route_key; Path=/; HttpOnly; SameSite=Lax\\x22 always;\\n        }\\n    }\\n}" > /etc/nginx/nginx.conf\n\
+    echo -e "worker_processes auto;\\npid /run/nginx.pid;\\n\\nevents {\\n    worker_connections 1024;\\n}\\n\\nhttp {\\n    client_max_body_size 0;\\n\\n    map \\$cookie_stroute \\$route_key {\\n        \\x22\\x22      \\$request_id;\\n        default \\$cookie_stroute;\\n    }\\n\\n    upstream streamlit_backend {\\n        hash \\$route_key consistent;\\n${UPSTREAM_SERVERS}    }\\n\\n    map \\$http_upgrade \\$connection_upgrade {\\n        default upgrade;\\n        \\x27\\x27 close;\\n    }\\n\\n    server {\\n        listen 0.0.0.0:8501;\\n\\n        location / {\\n            proxy_pass http://streamlit_backend;\\n            proxy_http_version 1.1;\\n            proxy_set_header Upgrade \\$http_upgrade;\\n            proxy_set_header Connection \\$connection_upgrade;\\n            proxy_set_header Host \\$host;\\n            proxy_set_header X-Real-IP \\$remote_addr;\\n            proxy_set_header X-Forwarded-For \\$proxy_add_x_forwarded_for;\\n            proxy_set_header X-Forwarded-Proto \\$scheme;\\n            proxy_read_timeout 86400;\\n            proxy_send_timeout 86400;\\n            proxy_buffering off;\\n            add_header Set-Cookie \\x22stroute=\\$route_key; Path=/; HttpOnly; SameSite=Lax\\x22 always;\\n        }\\n    }\\n}" > /etc/nginx/nginx.conf\n\
 \n\
     # Start Streamlit instances on internal ports (localhost only)\n\
     for i in $(seq 0 $((SERVER_COUNT - 1))); do\n\