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>

bootstrap/app.php

@@ -19,7 +19,7 @@ return Application::configure(basePath: dirname(__DIR__))
         $middleware->alias([
             'admin' => \App\Http\Middleware\EnsureUserIsAdmin::class,
             'workspace' => \App\Http\Middleware\EnsureUserHasWorkspace::class,
-            'folder.invitation' => \App\Http\Middleware\ValidateFolderInvitation::class,
+            'client-portal' => \App\Http\Middleware\ValidateClientPortalToken::class,
         ]);
 
         $middleware->web(append: [