fix(boot): auto-recover from stale chunks after a deploy

Deploys replace hashed chunk filenames; a tab that was already open can load a
chunk that no longer exists (404) and hit the error boundary ('THIS PAGE
SLAMMED'). Listen for Vite's vite:preloadError (and dynamic-import failures) and
reload once, guarded against loops.

src/main.tsx

@@ -76,6 +76,40 @@ import '@fontsource/barlow-condensed/700.css';
 })();
 
 
+/**
+ * STALE-DEPLOY SELF-HEAL
+ *
+ * Deploys replace hashed chunk filenames and delete the old ones. A tab that
+ * was already open still holds the previous manifest, so navigating to a lazy
+ * route loads a chunk that no longer exists (404) and the error boundary shows
+ * "THIS PAGE SLAMMED". Vite emits `vite:preloadError` for exactly this case.
+ *
+ * Reload once to pick up the new assets. The timestamp guard prevents a reload
+ * loop if a build is genuinely broken (the error boundary will show instead).
+ */
+(function recoverFromStaleChunks() {
+  const KEY = 'skatespots:chunk-reload-at';
+  const reload = () => {
+    try {
+      const last = Number(sessionStorage.getItem(KEY) || 0);
+      if (Date.now() - last < 15000) return; // already reloaded recently — don't loop
+      sessionStorage.setItem(KEY, String(Date.now()));
+    } catch {
+      /* sessionStorage unavailable — fall through and reload anyway */
+    }
+    window.location.reload();
+  };
+
+  window.addEventListener('vite:preloadError', reload);
+  window.addEventListener('unhandledrejection', (e) => {
+    const msg = String((e as PromiseRejectionEvent).reason?.message ?? '');
+    if (/dynamically imported module|Importing a module script failed|Loading chunk/i.test(msg)) {
+      reload();
+    }
+  });
+})();
+
+
 createRoot(document.getElementById("root")!).render(
   <ErrorBoundary>
     <App />