feat(tasks): complete task management system with Kanban, Calendar, notifications

- Add Task model with subtasks, priorities, status transitions, dates, hours
- Add Comment polymorphic model for tasks/issues/projects
- Livewire components: TaskManager (list+filters), TaskForm (modal), TaskDetail, TaskKanban (drag&drop), TaskCalendar (FullCalendar)
- TaskPolicy with permissions (view/create/edit/delete/assign/manage all)
- Notifications: assigned, status change, overdue, comment added
- Daily overdue notification job scheduled
- Dashboard widget unifies IssueTask + Task
- i18n: en/es/fr/ru (393 keys each)
- Routes, navigation, offline sync support
- 101 tests passing, Pint compliant on new files

app/Notifications/TaskAssignedNotification.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Models\Task;
+use Illuminate\Bus\Queueable;
+use Illuminate\Notifications\Notification;
+
+class TaskAssignedNotification extends Notification
+{
+    use Queueable;
+
+    public function __construct(public Task $task) {}
+
+    public function via($notifiable): array
+    {
+        return ['database'];
+    }
+
+    public function toArray($notifiable): array
+    {
+        return [
+            'type' => 'task_assigned',
+            'task_id' => $this->task->id,
+            'project_id' => $this->task->project_id,
+            'priority' => $this->task->priority,
+            'message' => "Se te ha asignado la tarea '{$this->task->title}'",
+        ];
+    }
+}