Fix SPA forward for /oidc/callback and /admin/* routes

The SPA catch-all was missing these paths, causing 404 when Authentik
redirected back to /oidc/callback after authentication.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cameleer3-server-app/src/main/java/com/cameleer3/server/app/web/SpaForwardController.java

@@ -16,7 +16,9 @@ public class SpaForwardController {
     @GetMapping(value = {
             "/login",
             "/executions",
-            "/executions/{path:[^\\.]*}"
+            "/executions/{path:[^\\.]*}",
+            "/oidc/callback",
+            "/admin/{path:[^\\.]*}"
     })
     public String forward() {
         return "forward:/index.html";