Set up immediate theme application and manual SW updates

Moved theme application logic to occur immediately on app initialization to prevent UI flash. Added a check to wait for all fonts to load before making the app visible and adjusted Service Worker behavior to require manual updates instead of auto-reloading.

frontend/src/main.jsx

@@ -4,7 +4,8 @@ import App from "./App.jsx";
 import { applyTheme, DEFAULT_THEME_KEY } from "./styles/themes";
 import { registerSW } from "virtual:pwa-register";
 
-// ✅ Theme VOR React setzen (kein Theme-Flash)
+async function bootstrap() {
+  // ✅ Theme sofort setzen
   try {
     const key = localStorage.getItem("hpTheme:guest") || DEFAULT_THEME_KEY;
     applyTheme(key);
@@ -12,17 +13,29 @@ try {
     applyTheme(DEFAULT_THEME_KEY);
   }
 
-// ✅ Preload Unlock (nach Theme!)
+  // ✅ Warten bis ALLE Fonts geladen sind
+  try {
+    if (document.fonts && document.fonts.ready) {
+      await document.fonts.ready;
+    }
+  } catch {
+    // ignore
+  }
+
+  // ✅ Erst JETZT sichtbar machen
   document.body.classList.remove("preload");
   document.body.classList.add("ready");
 
   ReactDOM.createRoot(document.getElementById("root")).render(<App />);
 
-// ✅ Service Worker NUR EINMAL registrieren
-const updateSW = registerSW({
+  // ✅ Service Worker – KEIN Auto-Reload mehr
+  registerSW({
     immediate: true,
     onNeedRefresh() {
-    updateSW(true);
-    window.location.reload();
+      console.info("Neue Version verfügbar – Reload manuell");
+      // optional: später Toast „Update verfügbar“
     },
   });
+}
+
+bootstrap();