fix: loyalty sidebar menu label and active state highlighting

- Rename menu item IDs to match URL last segments (terminal, cards,
  stats) so the sidebar active state comparison works correctly
- Change "Dashboard" label to "Terminal" for the loyalty terminal page
- Point menu route directly to /loyalty/terminal (skip redirect)
- Add "terminal" translation key in all locale files (en, de, fr, lb)

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

app/modules/loyalty/locales/fr.json

@@ -75,6 +75,7 @@
         "programs": "Programmes",
         "analytics": "Analytique",
         "dashboard": "Tableau de bord",
+        "terminal": "Terminal",
         "customer_cards": "Cartes clients",
         "statistics": "Statistiques"
     }