chore: add BMAD framework modules, folder features, and tooling configs

Includes BMAD bmb/bmm/cis/tea workflow modules, folder (declaration)
feature implementation (controllers, models, enums, views, tests),
claude/cursor command configs, and email templates.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Notifications/FolderMentionNotification.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Models\Folder;
+use App\Models\User;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Notifications\Messages\MailMessage;
+use Illuminate\Notifications\Notification;
+
+class FolderMentionNotification extends Notification implements ShouldQueue
+{
+    use Queueable;
+
+    public function __construct(
+        public Folder $folder,
+        public User $mentionedBy,
+        public string $message,
+    ) {}
+
+    /**
+     * @return array<string>
+     */
+    public function via(object $notifiable): array
+    {
+        return ['database', 'mail'];
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function toDatabase(object $notifiable): array
+    {
+        return [
+            'folder_id' => $this->folder->id,
+            'folder_title' => $this->folder->title,
+            'mentioned_by_id' => $this->mentionedBy->id,
+            'mentioned_by_name' => $this->mentionedBy->name,
+            'message' => $this->message,
+            'url' => route('folders.show', $this->folder),
+        ];
+    }
+
+    public function toMail(object $notifiable): MailMessage
+    {
+        return (new MailMessage)
+            ->subject('Vous avez été mentionné - '.$this->folder->title)
+            ->markdown('emails.folder-mention', [
+                'folderTitle' => $this->folder->title,
+                'mentionedByName' => $this->mentionedBy->name,
+                'message' => $this->message,
+                'url' => route('folders.show', $this->folder),
+            ]);
+    }
+}