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/Policies/TaskPolicy.php

@@ -0,0 +1,122 @@
+<?php
+
+namespace App\Policies;
+
+use App\Models\Task;
+use App\Models\User;
+
+class TaskPolicy
+{
+    /**
+     * Determine whether the user can view any tasks.
+     */
+    public function viewAny(User $user): bool
+    {
+        return $user->can('view tasks') || $user->can('manage all tasks');
+    }
+
+    /**
+     * Determine whether the user can view the task.
+     */
+    public function view(User $user, Task $task): bool
+    {
+        if ($user->can('manage all tasks')) {
+            return true;
+        }
+        if (! $user->can('view tasks')) {
+            return false;
+        }
+
+        return $task->project->users()->where('user_id', $user->id)->exists();
+    }
+
+    /**
+     * Determine whether the user can create tasks.
+     */
+    public function create(User $user, $project = null): bool
+    {
+        if ($user->can('manage all tasks')) {
+            return true;
+        }
+        if (! $user->can('create tasks')) {
+            return false;
+        }
+        if ($project) {
+            return $project->users()->where('user_id', $user->id)->exists();
+        }
+
+        return true;
+    }
+
+    /**
+     * Determine whether the user can update the task.
+     */
+    public function update(User $user, Task $task): bool
+    {
+        if ($user->can('manage all tasks')) {
+            return true;
+        }
+        if (! $user->can('edit tasks')) {
+            return false;
+        }
+
+        // Own tasks or tasks in own projects
+        return $task->created_by === $user->id
+            || $task->project->users()->where('user_id', $user->id)->exists();
+    }
+
+    /**
+     * Determine whether the user can delete the task.
+     */
+    public function delete(User $user, Task $task): bool
+    {
+        if ($user->can('manage all tasks')) {
+            return true;
+        }
+        if (! $user->can('delete tasks')) {
+            return false;
+        }
+
+        // Only creator or project admin can delete
+        return $task->created_by === $user->id
+            || $task->project->users()->where('user_id', $user->id)->wherePivot('role_in_project', 'admin')->exists();
+    }
+
+    /**
+     * Determine whether the user can assign/reassign the task.
+     */
+    public function assign(User $user, Task $task): bool
+    {
+        if ($user->can('manage all tasks')) {
+            return true;
+        }
+        if (! $user->can('assign tasks')) {
+            return false;
+        }
+
+        return $task->project->users()->where('user_id', $user->id)->exists();
+    }
+
+    /**
+     * Determine whether the user can restore the task.
+     */
+    public function restore(User $user, Task $task): bool
+    {
+        if ($user->can('manage all tasks')) {
+            return true;
+        }
+        if (! $user->can('edit tasks')) {
+            return false;
+        }
+
+        return $task->project->users()->where('user_id', $user->id)->exists();
+    }
+
+    /**
+     * Determine whether the user can permanently delete the task.
+     */
+    public function forceDelete(User $user, Task $task): bool
+    {
+        return $user->can('manage all tasks');
+    }
+}