feat(06-task-title-ai): complete OpenAI task title suggestions

Phase 6 complete:

- add AI title generator service using gpt-5-nano

- add task popup button for biuro@project-pro.pl

- add AJAX endpoint returning title suggestions without auto-save

autoload/controls/class.Tasks.php

@@ -372,6 +372,51 @@ class Tasks
     exit;
   }
 
+  static public function task_generate_title()
+  {
+    global $user, $settings;
+
+    $response = [ 'status' => 'error', 'msg' => 'Nie udało się wygenerować tytułu zadania.' ];
+
+    if ( !$user or !isset( $user['email'] ) or strtolower( trim( (string)$user['email'] ) ) !== 'biuro@project-pro.pl' )
+    {
+      echo json_encode( [ 'status' => 'error', 'msg' => 'Brak uprawnień do generowania tytułu.' ] );
+      exit;
+    }
+
+    $task_id = (int)\S::get( 'task_id' );
+    if ( !$task_id )
+    {
+      echo json_encode( [ 'status' => 'error', 'msg' => 'Nieprawidłowe zadanie.' ] );
+      exit;
+    }
+
+    $task = \factory\Tasks::task_details( $task_id, (int)$user['id'] );
+    if ( !is_array( $task ) or !isset( $task['id'] ) )
+    {
+      echo json_encode( [ 'status' => 'error', 'msg' => 'Nie znaleziono zadania.' ] );
+      exit;
+    }
+
+    $task_text = isset( $task['text'] ) ? trim( (string)$task['text'] ) : '';
+    if ( $task_text === '' )
+    {
+      echo json_encode( [ 'status' => 'error', 'msg' => 'Zadanie nie ma treści do wygenerowania tytułu.' ] );
+      exit;
+    }
+
+    $api_key = isset( $settings['openai_api_key'] ) ? trim( (string)$settings['openai_api_key'] ) : '';
+    $model = isset( $settings['openai_task_title_model'] ) ? trim( (string)$settings['openai_task_title_model'] ) : 'gpt-5-nano';
+    $generator = new \Domain\Tasks\TaskTitleGenerator();
+    $result = $generator -> generate( $api_key, $model, $task_text );
+
+    if ( is_array( $result ) and isset( $result['status'] ) )
+      $response = $result;
+
+    echo json_encode( $response );
+    exit;
+  }
+
   static public function task_change_text() {
     global $mdb;