🛟 fix: Auto-Recover from Stale Service Worker Assets After Deploys (#13686)

* 🛟 fix: Auto-Recover from Stale Service Worker Assets After Deploys

- 404 missing static assets in the SPA fallback instead of serving index.html
- inline recovery script unregisters stale SWs and reloads once on chunk failure
- route vite:preloadError into the same recovery path for stale lazy chunks

* 🛟 fix: Address Review — SW-Side Recovery, Scoped Unregister, Shared Fallback

- importScripts'd sw-heal.js pings window clients on activation and reloads
  ones that can't pong: stale pages carry no recovery code of their own
- scope SW unregistration to the deployment base for subpath installs
- preventDefault vite:preloadError only when a recovery reload was initiated
- extract createSpaFallback and apply the asset 404 guard to experimental.js

api/server/utils/staticCache.js

@@ -38,7 +38,8 @@ function staticCache(staticPath, options = {}) {
       fileName === 'index.html' ||
       fileName.endsWith('.webmanifest') ||
       fileName === 'manifest.json' ||
-      fileName === 'sw.js'
+      fileName === 'sw.js' ||
+      fileName === 'sw-heal.js'
     ) {
       res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate');
     } else {