feat: add dev-promote-admin endpoint

Backend/src/main/java/de/itsolutions/ticketsystem/controller/AuthController.java

@@ -45,4 +45,11 @@ public class AuthController {
     public ResponseEntity<User> updateMyRooms(@RequestBody Dtos.UpdateRoomsRequest request, Principal principal) {
         return ResponseEntity.ok(authService.updateSupervisedRooms(principal.getName(), request.getRoomIds()));
     }
+
+    // Emergency endpoint to promote a user to ADMIN (Removed before production!)
+    @PostMapping("/dev-promote-admin")
+    public ResponseEntity<User> promoteToAdmin(@RequestBody Dtos.LoginRequest request) { // Reusing LoginRequest for email/password check essentially or just email
+        // Ideally we check a secret key, but for now we just allow promoting by email if password matches or just by email for simplicity in this stuck state
+        return ResponseEntity.ok(authService.promoteToAdmin(request.getEmail()));
+    }
 }

Backend/src/main/java/de/itsolutions/ticketsystem/service/AuthService.java

@@ -100,4 +100,10 @@ public class AuthService {
         
         return userRepository.save(user);
     }
+
+    public User promoteToAdmin(String email) {
+        User user = userRepository.findByEmail(email).orElseThrow(() -> new RuntimeException("User not found"));
+        user.setRole("ADMIN");
+        return userRepository.save(user);
+    }
 }