Remove duplicate checklists functionality

Checklists were duplicating subtasks functionality. Removed:
- Migration for task_checklists table
- TaskChecklistModel
- Checklist methods from TaskService
- Checklist routes from Routes.php
- Checklist controller methods
- Checklist UI section from show.twig
- Checklist JavaScript functions

Updated TASKS_MODULE_ROADMAP.md

app/Modules/Tasks/Config/Routes.php

@@ -32,11 +32,6 @@ $routes->group('tasks', ['filter' => ['org', 'subscription:tasks'], 'namespace'
     $routes->post('(:num)/subtasks', 'TasksController::addSubtask/$1');
     $routes->post('(:num)/subtasks/(:num)/toggle', 'TasksController::toggleSubtask/$1/$2');
     $routes->post('(:num)/subtasks/(:num)/delete', 'TasksController::deleteSubtask/$1/$2');
-
-    // Checklists API
-    $routes->post('(:num)/checklists', 'TasksController::addChecklistItem/$1');
-    $routes->post('(:num)/checklists/(:num)/toggle', 'TasksController::toggleChecklistItem/$1/$2');
-    $routes->post('(:num)/checklists/(:num)/delete', 'TasksController::deleteChecklistItem/$1/$2');
 });
 
 // API Routes для Tasks