feat: implement CDN URL support for asset loading and add replacement script

frontend/scripts/replace-standalone-build-variable.sh

@@ -10,7 +10,13 @@ fi
 
 echo "Replacing pre-baked value.."
 
+# Replace in JS files in assets directory
 find assets -type f -name "*.js" |
 while read file; do
     sed -i "s|$ORIGINAL|$REPLACEMENT|g" "$file"
 done
+
+# Replace in index.html (for asset references)
+if [ -f "index.html" ]; then
+    sed -i "s|$ORIGINAL|$REPLACEMENT|g" "index.html"
+fi

frontend/vite.config.ts

@@ -29,14 +29,14 @@ export default defineConfig(({ mode }) => {
     "0.0.1"
   ).replaceAll(".", "-");
 
-  // Optional CDN URL for static assets (e.g., https://cdn.example.com)
-  // When set, all static assets will be served from this URL instead of the same origin.
-  // This is useful for serving assets from a CDN subdomain while keeping API calls on the main domain.
-  // If not set, assets are served from the same origin (backward compatible).
+  // CDN URL for static assets in /assets/* only.
+  // Docker: Set CDN_URL env var at runtime (placeholder replaced at container startup).
+  // Direct build: Use --build-arg CDN_URL=https://... or VITE_CDN_URL env var.
+  // Default: Empty = same-origin asset loading.
   const cdnUrl = env.VITE_CDN_URL || "";
 
   return {
-    base: cdnUrl || "/",
+    base: "/",
     server: {
       allowedHosts,
       host: true,
@@ -59,6 +59,15 @@ export default defineConfig(({ mode }) => {
         }
       }
     },
+    experimental: {
+      // Only apply CDN URL to files in /assets/* directory
+      renderBuiltUrl(filename) {
+        if (filename.startsWith("assets/")) {
+          return `${cdnUrl}/${filename}`;
+        }
+        return `/${filename}`;
+      }
+    },
     plugins: [
       tsconfigPaths(),
       nodePolyfills({