feat: complete Epic 0 — foundation migration & infrastructure setup

Stories 0.2-0.5: rename folders→declarations (backend+frontend), configure
Redis for cache/queue/sessions, add foundation database migrations
(permissions, archived_at), replace DeclarationStatus enum with architecture
lifecycle values, create DeclarationObserver for status transition validation
and auto-archive, fix controller status transitions to respect observer rules.

93 tests pass (240 assertions).

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

app/Http/Middleware/ValidateClientPortalToken.php

@@ -2,12 +2,12 @@
 
 namespace App\Http\Middleware;
 
-use App\Models\FolderInvitation;
+use App\Models\DeclarationInvitation;
 use Closure;
 use Illuminate\Http\Request;
 use Symfony\Component\HttpFoundation\Response;
 
-class ValidateFolderInvitation
+class ValidateClientPortalToken
 {
     /**
      * Handle an incoming request.
@@ -18,16 +18,16 @@ class ValidateFolderInvitation
     {
         $token = $request->route('token');
 
-        $invitation = FolderInvitation::query()
+        $invitation = DeclarationInvitation::query()
             ->where('token', $token)
-            ->with(['folder.client', 'folder.assignee', 'folder.creator'])
+            ->with(['declaration.client', 'declaration.assignee', 'declaration.creator'])
             ->first();
 
         if (! $invitation || ! $invitation->isValid()) {
             abort(404, 'Lien invalide ou expiré.');
         }
 
-        $request->attributes->set('folder_invitation', $invitation);
+        $request->attributes->set('declaration_invitation', $invitation);
 
         return $next($request);
     }