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/Http/Controllers/FolderMentionController.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Http\Requests\StoreFolderMentionRequest;
+use App\Models\Folder;
+use App\Models\User;
+use App\Models\Workspace;
+use App\Notifications\FolderMentionNotification;
+use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Cache;
+
+class FolderMentionController extends Controller
+{
+    protected function currentWorkspace(Request $request): Workspace
+    {
+        $workspaceId = $request->session()->get('current_workspace_id');
+
+        return Workspace::query()->findOrFail($workspaceId);
+    }
+
+    protected function authorizeFolder(Workspace $workspace, Folder $folder): void
+    {
+        if ($folder->workspace_id !== $workspace->id) {
+            abort(404);
+        }
+    }
+
+    public function store(StoreFolderMentionRequest $request, Folder $folder): RedirectResponse
+    {
+        $workspace = $this->currentWorkspace($request);
+        $this->authorizeFolder($workspace, $folder);
+
+        $userRole = $workspace->users()
+            ->where('users.id', $request->user()->id)
+            ->first()
+            ?->pivot
+            ?->role
+            ?->value;
+
+        if (! in_array($userRole, ['owner', 'manager'])) {
+            abort(403);
+        }
+
+        $validated = $request->validated();
+        $targetUser = User::findOrFail($validated['user_id']);
+
+        $targetUser->notify(new FolderMentionNotification(
+            $folder,
+            $request->user(),
+            $validated['message'],
+        ));
+
+        Cache::forget("user:{$targetUser->id}:unread_notifications");
+
+        return back()->with('flash', ['type' => 'success', 'message' => 'Notification envoyée.']);
+    }
+}