feat(roles): add admin store roles page, permission i18n, and menu integration

- Add admin store roles page with merchant→store cascading for superadmin
  and store-only selection for platform admin
- Add permission catalog API with translated labels/descriptions (en/fr/de/lb)
- Add permission translations to all 15 module locale files (60 files total)
- Add info icon tooltips for permission descriptions in role editor
- Add store roles menu item and admin menu item in module definition
- Fix store-selector.js URL construction bug when apiEndpoint has query params
- Add admin store roles API (CRUD + platform scoping)
- Add integration tests for admin store roles and permission catalog

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

app/modules/messaging/locales/lb.json

@@ -60,5 +60,13 @@
         "messages": "Messagen",
         "notifications": "Notifikatiounen",
         "email_templates": "E-Mail-Virlagen"
+    },
+    "permissions": {
+        "view_messages": "Messagen kucken",
+        "view_messages_desc": "Messagen a Conversatiounen kucken",
+        "send_messages": "Messagen schécken",
+        "send_messages_desc": "Messagen u Clienten schécken",
+        "manage_templates": "Schablounen verwalten",
+        "manage_templates_desc": "Messageschablounen erstellen an änneren"
     }
 }