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/Requests/UpdateWorkspaceRequest.php

@@ -34,7 +34,7 @@ class UpdateWorkspaceRequest extends FormRequest
             'user_ids' => ['array'],
             'user_ids.*' => ['integer', 'exists:users,id'],
             'user_roles' => ['nullable', 'array'],
-            'user_roles.*' => ['string', 'in:' . implode(',', WorkspaceUserRole::getValues())],
+            'user_roles.*' => ['string', 'in:'.implode(',', WorkspaceUserRole::getValues())],
         ];
     }
 }