Fix crash bugs and secure webhook/TMDB key

- Add missing MovieController::remove/markWatched (routes called undefined methods)
- Fix linkPartner(): commit() was unreachable after an early return, so partner
  linking was never actually persisted in the DB
- Add missing removeMovie/markWatched functions in app.js
- webhook.php now verifies a GitHub HMAC signature before running git reset --hard
- Move TMDB API key server-side via a new TmdbController proxy (tmdb-search/tmdb-details)
  instead of exposing it in client-side JS

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

controllers/MovieController.php

@@ -42,9 +42,29 @@ class MovieController {
         
         // 3. On renvoie le JSON
         echo json_encode([
-            "success" => true, 
-            "partner_id" => $realPartnerId, 
+            "success" => true,
+            "partner_id" => $realPartnerId,
             "lists" => $lists
         ]);
     }
+
+    public function remove($data) {
+        if (!isset($data['movie_id'])) {
+            http_response_code(400);
+            echo json_encode(["error" => "ID du film manquant"]);
+            return;
+        }
+        $res = $this->movieModel->remove($data['movie_id'], $data['user_id']);
+        echo json_encode(["success" => $res]);
+    }
+
+    public function markWatched($data) {
+        if (!isset($data['movie_id'])) {
+            http_response_code(400);
+            echo json_encode(["error" => "ID du film manquant"]);
+            return;
+        }
+        $res = $this->movieModel->markWatched($data['movie_id'], $data['user_id']);
+        echo json_encode(["success" => $res]);
+    }
 }