feat(docker, nginx): optimize Dockerfile for frontend build and enhance demo server configuration with mock files and improved WebSocket feedback

Dockerfile.demo

@@ -8,7 +8,9 @@ FROM node:${NODE_VERSION}-alpine@${NODE_ALPINE_SHA256} AS build-frontend
 WORKDIR /src
 
 COPY package.json vite.config.js pnpm-lock.yaml tailwind.config.js postcss.config.js ./
-COPY meshchatx ./meshchatx
+# Copy only the frontend source and version info to speed up builds and reduce image size
+COPY meshchatx/src/frontend ./meshchatx/src/frontend
+COPY meshchatx/src/version.py ./meshchatx/src/version.py
 
 RUN corepack enable && corepack prepare pnpm@latest --activate
 

nginx.demo.conf

@@ -24,10 +24,29 @@ server {
         try_files $uri =404;
     }
 
-    # Handle manifest.json and service-worker.js specifically
-    location ~* (manifest\.json|service-worker\.js) {
+    # Mocking missing critical files for demo stability
+    location = /manifest.json {
         add_header Cache-Control "no-cache";
-        try_files $uri =404;
+        add_header Content-Type application/json;
+        try_files $uri @mock_manifest;
+    }
+    location @mock_manifest {
+        return 200 '{"name": "MeshChat Demo", "short_name": "MeshChat", "start_url": "/", "display": "standalone", "icons": [{"src": "/favicons/favicon-512x512.png", "sizes": "512x512", "type": "image/png"}]}';
+    }
+
+    location = /service-worker.js {
+        add_header Cache-Control "no-cache";
+        add_header Content-Type application/javascript;
+        try_files $uri @mock_sw;
+    }
+    location @mock_sw {
+        return 200 '// Mock Service Worker\nself.addEventListener("fetch", (event) => {});';
+    }
+
+    # Mock Codec2 scripts to prevent load failures in demo mode
+    location ^~ /assets/js/codec2-emscripten/ {
+        add_header Content-Type application/javascript;
+        try_files $uri =200;
     }
 
     # Gzip compression
@@ -215,6 +234,7 @@ server {
         add_header Content-Type application/json;
     }
 
+    # Improved WebSocket handler
     location /ws {
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
@@ -224,8 +244,12 @@ server {
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
         proxy_set_header X-Forwarded-Proto $scheme;
 
-        # In demo mode, there is no WebSocket backend service.
-        # This block is configured to support WSS upgrades from a reverse proxy.
+        # In demo mode, returning 200 for non-WS requests provides better feedback
+        if ($http_upgrade != "websocket") {
+            return 200 "WebSocket Mock Endpoint (Active)";
+        }
+
+        # For actual WS connection attempts, we still return 503 as there is no backend server.
         return 503;
     }