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/checkout/locales/en.json

@@ -1,4 +1,10 @@
 {
+  "permissions": {
+    "view_settings": "View Checkout Settings",
+    "view_settings_desc": "View checkout configuration",
+    "manage_settings": "Manage Checkout Settings",
+    "manage_settings_desc": "Configure checkout process and options"
+  },
   "storefront": {
     "welcome": "Welcome to our store",
     "browse_products": "Browse Products",