Fix Cors-Issues

Author: Sascha-droid

backend/src/main/java/org/example/app/general/common/security/AuthCookieFilter.java

@@ -33,10 +33,10 @@ public void filter(ContainerRequestContext requestContext) throws IOException {
 
         if (!isValidSession(sessionCookie.getValue())) {
             sessionService.storeSession(sessionCookie.getValue(), "", originalUrl);
-            // Redirect to Keycloak if no valid session found
             requestContext.abortWith(
-                    Response.status(Response.Status.FOUND)
-                            .header("Location", authRedirectUrl)
+                    Response.status(Response.Status.UNAUTHORIZED)
+                            .entity("{\"redirectUrl\": \"" + authRedirectUrl + "\"}")
+                            .type(MediaType.APPLICATION_JSON)
                             .build()
             );
         }