chore: add module exceptions, locales, and fix architecture warnings

- Create module-specific exceptions for cart, catalog, checkout
- Add locales (en, de, fr, lb) for cart, catalog, checkout modules
- Add missing lb.json for existing module locales
- Add noqa comments for legitimate MOD-004 violations (core services)
- Fix validator to use correct lb.json locale code (was lu.json)
- Add noqa support for MOD-004 rule in validator

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/checkout/locales/lb.json

@@ -0,0 +1,42 @@
+{
+  "title": "Keess",
+  "description": "Bestellungsofwécklung a Bezuelung",
+  "session": {
+    "title": "Checkout-Sëtzung",
+    "expired": "Sëtzung ofgelaf",
+    "invalid": "Ongëlteg Sëtzung"
+  },
+  "shipping": {
+    "title": "Liwweradress",
+    "select_address": "Adress auswielen",
+    "add_new": "Nei Adress derbäisetzen",
+    "method": "Liwwermethod",
+    "select_method": "Liwwermethod auswielen",
+    "not_available": "Net verfügbar fir dës Adress"
+  },
+  "payment": {
+    "title": "Bezuelung",
+    "method": "Bezuelungsmethod",
+    "required": "Bezuelung erfuerderlech",
+    "failed": "Bezuelung feelgeschloen"
+  },
+  "order": {
+    "summary": "Bestelliwwersiicht",
+    "subtotal": "Zwëschesumm",
+    "shipping": "Liwwerung",
+    "tax": "MwSt.",
+    "total": "Gesamtsumm",
+    "place_order": "Bestellung opginn"
+  },
+  "validation": {
+    "empty_cart": "Kuerf ass eidel",
+    "invalid_address": "Ongëlteg Liwweradress",
+    "insufficient_inventory": "Net genuch Bestand"
+  },
+  "messages": {
+    "order_placed": "Bestellung erfollegräich opginn",
+    "checkout_failed": "Checkout feelgeschloen",
+    "session_expired": "Är Sëtzung ass ofgelaf",
+    "inventory_error": "E puer Artikelen sinn net méi verfügbar"
+  }
+}