✨ Add lecturer cleanup job and update profile update functionality

- 🧹 Introduce `lecturers:cleanup` command to delete lecturers without associated courses or events, merging their items into "Einundzwanzig."
- ⚙️ Add `update` method to `UserController` for handling profile updates, allowing name changes while restricting role modifications.
- 🌐 Register `PATCH /api/user` route for profile updates and update related API tests.
- 🧪 Add feature and console tests for `lecturers:cleanup`, covering dry-run, forced deletion, and edge cases.

routes/api.php

@@ -42,6 +42,7 @@ Route::middleware('auth:sanctum')
     ->as('api.')
     ->group(function () {
         Route::get('user', UserController::class)->name('user');
+        Route::patch('user', [UserController::class, 'update'])->name('user.update');
 
         Route::post('courses', [CourseController::class, 'store'])
             ->name('courses.store');