fix(web-app): Caddy templates für text/html + SW-Bypass für config.json

Co-authored-by: Junie <junie@jetbrains.com>

config/docker/caddy/web-app/Caddyfile

@@ -20,10 +20,10 @@
 # Komprimierung
   encode gzip zstd
 
-# Caddy-Template-Engine für config.json (liefert API_BASE_URL & KEYCLOAK_URL an den Browser)
+# Caddy-Template-Engine: ersetzt {{.Env.VAR}} in index.html UND config.json
   templates {
-              mime application/json
-            }
+    mime text/html application/json
+  }
 
 # API-Proxy (höchste Priorität – vor dem SPA-Fallback)
   handle /api/* {

frontend/shells/meldestelle-portal/src/jsMain/resources/sw.js

@@ -68,6 +68,12 @@ self.addEventListener('fetch', (event) => {
     return;
   }
 
+  // Laufzeit-Config immer direkt vom Netzwerk – niemals aus dem Cache
+  if (url.pathname === '/config.json') {
+    event.respondWith(fetch(req).catch(() => new Response('{}', { status: 200, headers: { 'Content-Type': 'application/json' } })));
+    return;
+  }
+
   // Avoid noisy errors for favicon during dev/prod when missing
   if (url.pathname === '/favicon.ico') {
     event.respondWith(