Conditionally generate vendor import map outside cloud builds (#6559)

## Summary
- gate vendor import-map generation behind non-cloud distributions
- keep cloud bundles slim while preserving prebuilt chunks for
desktop/localhost builds
- document the conditional to guide future CDN/cache work

## Testing
- [ ] DISTRIBUTION=cloud pnpm build
- [ ] DISTRIBUTION=desktop pnpm build

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6559-Conditionally-generate-vendor-import-map-outside-cloud-builds-2a06d73d3650819d96a0e2b6c006baf1)
by [Unito](https://www.unito.io)

vite.config.mts

@@ -222,6 +222,9 @@ export default defineConfig({
       : [vue()]),
     tailwindcss(),
     comfyAPIPlugin(IS_DEV),
+    // Skip import-map generation for cloud builds to keep bundle small
+    ...(DISTRIBUTION !== 'cloud'
+      ? [
           generateImportMapPlugin([
             {
               name: 'vue',
@@ -256,7 +259,9 @@ export default defineConfig({
                 }
               }
             }
-    ]),
+          ])
+        ]
+      : []),
 
     Icons({
       compiler: 'vue3',