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/billing/locales/en.json

@@ -81,6 +81,18 @@
         "current": "Current Plan",
         "recommended": "Recommended"
     },
+    "permissions": {
+        "view_tiers": "View Tiers",
+        "view_tiers_desc": "View subscription tier details",
+        "manage_tiers": "Manage Tiers",
+        "manage_tiers_desc": "Create and configure subscription tiers",
+        "view_subscriptions": "View Subscriptions",
+        "view_subscriptions_desc": "View store subscription details",
+        "manage_subscriptions": "Manage Subscriptions",
+        "manage_subscriptions_desc": "Manage store subscriptions and billing",
+        "view_invoices": "View Invoices",
+        "view_invoices_desc": "View billing invoices and history"
+    },
     "messages": {
         "subscription_updated": "Subscription updated successfully",
         "tier_created": "Tier created successfully",