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/Livewire/Tasks/TaskDetail.php

@@ -0,0 +1,177 @@
+<?php
+
+namespace App\Livewire\Tasks;
+
+use App\Models\Comment;
+use App\Models\Project;
+use App\Models\Task;
+use App\Models\User;
+use Illuminate\Support\Facades\Auth;
+use Illuminate\Support\Str;
+use Livewire\Attributes\Layout;
+use Livewire\Component;
+use Livewire\WithFileUploads;
+
+#[Layout('layouts.app')]
+class TaskDetail extends Component
+{
+    use WithFileUploads;
+
+    public Task $task;
+
+    public ?Project $project = null;
+
+    // Comment form
+    public $commentBody = '';
+
+    public $editingCommentId = null;
+
+    public $editingCommentBody = '';
+
+    // Subtask form
+    public $subtaskTitle = '';
+
+    protected $listeners = ['tasksChanged' => '$refresh', 'commentAdded' => '$refresh', 'subtaskAdded' => '$refresh'];
+
+    public function mount(Task $task): void
+    {
+        $this->task = $task->load(['project', 'phase', 'assignee', 'creator', 'completer', 'subtasks', 'media', 'comments.user', 'comments.replies.user']);
+        $this->project = $this->task->project;
+
+        abort_unless(Auth::user()->can('view', $this->task), 403);
+    }
+
+    public function addComment(): void
+    {
+        $this->validate(['commentBody' => 'required|string|max:5000']);
+
+        $this->task->comments()->create([
+            'user_id' => Auth::id(),
+            'body' => $this->commentBody,
+        ]);
+
+        $this->commentBody = '';
+        $this->dispatch('commentAdded');
+        $this->dispatch('tasksChanged');
+    }
+
+    public function startEditComment($commentId): void
+    {
+        $comment = $this->task->comments()->find($commentId);
+        if ($comment && $comment->user_id === Auth::id()) {
+            $this->editingCommentId = $commentId;
+            $this->editingCommentBody = $comment->body;
+        }
+    }
+
+    public function saveEditComment(): void
+    {
+        $this->validate(['editingCommentBody' => 'required|string|max:5000']);
+
+        $comment = Comment::find($this->editingCommentId);
+        if ($comment && $comment->user_id === Auth::id()) {
+            $comment->update(['body' => $this->editingCommentBody]);
+        }
+
+        $this->editingCommentId = null;
+        $this->editingCommentBody = '';
+        $this->dispatch('commentAdded');
+    }
+
+    public function cancelEditComment(): void
+    {
+        $this->editingCommentId = null;
+        $this->editingCommentBody = '';
+    }
+
+    public function deleteComment($commentId): void
+    {
+        $comment = Comment::find($commentId);
+        if ($comment && ($comment->user_id === Auth::id() || Auth::user()->can('manage all tasks'))) {
+            $comment->delete();
+            $this->dispatch('commentAdded');
+        }
+    }
+
+    public function addSubtask(): void
+    {
+        $this->validate(['subtaskTitle' => 'required|string|max:255']);
+
+        $maxOrder = $this->task->subtasks()->max('order') ?? 0;
+
+        $this->task->subtasks()->create([
+            'title' => $this->subtaskTitle,
+            'status' => 'pending',
+            'priority' => 'medium',
+            'project_id' => $this->task->project_id,
+            'phase_id' => $this->task->phase_id,
+            'parent_task_id' => $this->task->id,
+            'created_by' => Auth::id(),
+            'order' => $maxOrder + 1,
+            'uuid' => Str::uuid(),
+        ]);
+
+        $this->subtaskTitle = '';
+        $this->dispatch('subtaskAdded');
+        $this->dispatch('tasksChanged');
+    }
+
+    public function updateSubtaskStatus(Task $subtask, string $status): void
+    {
+        abort_unless(Auth::user()->can('update', $subtask), 403);
+
+        $data = ['status' => $status];
+        if ($status === 'completed') {
+            $data['completed_at'] = now();
+            $data['completed_by'] = Auth::id();
+        } elseif ($subtask->status === 'completed') {
+            $data['completed_at'] = null;
+            $data['completed_by'] = null;
+        }
+
+        $subtask->update($data);
+        $this->dispatch('tasksChanged');
+    }
+
+    public function deleteSubtask(Task $subtask): void
+    {
+        abort_unless(Auth::user()->can('delete', $subtask), 403);
+        $subtask->delete();
+        $this->dispatch('tasksChanged');
+    }
+
+    public function changeStatus(string $status): void
+    {
+        abort_unless(Auth::user()->can('update', $this->task), 403);
+
+        $oldStatus = $this->task->status;
+        $data = ['status' => $status];
+
+        if ($oldStatus !== 'completed' && $status === 'completed') {
+            $data['completed_at'] = now();
+            $data['completed_by'] = Auth::id();
+        } elseif ($oldStatus === 'completed' && $status !== 'completed') {
+            $data['completed_at'] = null;
+            $data['completed_by'] = null;
+        }
+
+        $this->task->update($data);
+        $this->task->refresh();
+        $this->dispatch('tasksChanged');
+    }
+
+    public function render()
+    {
+        $assignees = User::whereHas('assignedTasks', function ($q) {
+            if ($this->project) {
+                $q->where('project_id', $this->project->id);
+            }
+        })->get(['id', 'name']);
+
+        return view('livewire.tasks.task-detail', [
+            'assignees' => $assignees,
+            'statusOptions' => Task::statusOptions(),
+            'priorityOptions' => Task::priorityOptions(),
+        ]);
+    }
+}