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/definition.py

@@ -155,21 +155,21 @@ loyalty_module = ModuleDefinition(
                 order=35,
                 items=[
                     MenuItemDefinition(
-                        id="loyalty",
-                        label_key="loyalty.menu.dashboard",
+                        id="terminal",
+                        label_key="loyalty.menu.terminal",
                         icon="gift",
-                        route="/store/{store_code}/loyalty",
+                        route="/store/{store_code}/loyalty/terminal",
                         order=10,
                     ),
                     MenuItemDefinition(
-                        id="loyalty-cards",
+                        id="cards",
                         label_key="loyalty.menu.customer_cards",
                         icon="identification",
                         route="/store/{store_code}/loyalty/cards",
                         order=20,
                     ),
                     MenuItemDefinition(
-                        id="loyalty-stats",
+                        id="stats",
                         label_key="loyalty.menu.statistics",
                         icon="chart-bar",
                         route="/store/{store_code}/loyalty/stats",