Add bnfexpress signed admin client and AI Agent Filament UI

- Modules\Shared\Bnfexpress\BnfexpressAdminClient: HMAC-signed HTTP client
  for bnfexpress's admin API (EV FAQs, agent instructions, chat history),
  with a bnfexpress:smoke-test command and full unit coverage.
- New ai-agent module: Filament pages to manage EV FAQs, publish/roll back
  agent instruction versions, and browse EV chat history + transcripts.
- New manage_ai_agent permission (super_admin/admin).
- Recorded .ai/rules for the client's auth scheme and non-Resource
  Filament page/table testing gotchas.

app-modules/identity/database/seeders/RolePermissionSeeder.php

@@ -26,6 +26,7 @@ class RolePermissionSeeder extends Seeder
         'view_customers',
         'manage_settings',
         'view_reports',
+        'manage_ai_agent',
     ];
 
     /**
@@ -46,6 +47,7 @@ class RolePermissionSeeder extends Seeder
             'view_customers',
             'manage_settings',
             'view_reports',
+            'manage_ai_agent',
         ],
         'admin' => [
             'manage_catalog',
@@ -59,6 +61,7 @@ class RolePermissionSeeder extends Seeder
             'view_customers',
             'manage_settings',
             'view_reports',
+            'manage_ai_agent',
         ],
         'support' => [
             'view_bookings',