refactor: complete module-driven architecture migration

This commit completes the migration to a fully module-driven architecture:

## Models Migration
- Moved all domain models from models/database/ to their respective modules:
  - tenancy: User, Admin, Vendor, Company, Platform, VendorDomain, etc.
  - cms: MediaFile, VendorTheme
  - messaging: Email, VendorEmailSettings, VendorEmailTemplate
  - core: AdminMenuConfig
- models/database/ now only contains Base and TimestampMixin (infrastructure)

## Schemas Migration
- Moved all domain schemas from models/schema/ to their respective modules:
  - tenancy: company, vendor, admin, team, vendor_domain
  - cms: media, image, vendor_theme
  - messaging: email
- models/schema/ now only contains base.py and auth.py (infrastructure)

## Routes Migration
- Moved admin routes from app/api/v1/admin/ to modules:
  - menu_config.py -> core module
  - modules.py -> tenancy module
  - module_config.py -> tenancy module
- app/api/v1/admin/ now only aggregates auto-discovered module routes

## Menu System
- Implemented module-driven menu system with MenuDiscoveryService
- Extended FrontendType enum: PLATFORM, ADMIN, VENDOR, STOREFRONT
- Added MenuItemDefinition and MenuSectionDefinition dataclasses
- Each module now defines its own menu items in definition.py
- MenuService integrates with MenuDiscoveryService for template rendering

## Documentation
- Updated docs/architecture/models-structure.md
- Updated docs/architecture/menu-management.md
- Updated architecture validation rules for new exceptions

## Architecture Validation
- Updated MOD-019 rule to allow base.py in models/schema/
- Created core module exceptions.py and schemas/ directory
- All validation errors resolved (only warnings remain)

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

app/modules/catalog/locales/de.json

@@ -1,49 +1,64 @@
 {
-  "title": "Produktkatalog",
-  "description": "Produktkatalogverwaltung für Händler",
   "products": {
     "title": "Produkte",
-    "subtitle": "Verwalten Sie Ihren Produktkatalog",
-    "create": "Produkt erstellen",
-    "edit": "Produkt bearbeiten",
-    "delete": "Produkt löschen",
-    "empty": "Keine Produkte gefunden",
-    "empty_search": "Keine Produkte entsprechen Ihrer Suche"
-  },
-  "product": {
-    "name": "Produktname",
-    "description": "Beschreibung",
-    "sku": "Artikelnummer",
+    "product": "Produkt",
+    "add_product": "Produkt hinzufügen",
+    "edit_product": "Produkt bearbeiten",
+    "delete_product": "Produkt löschen",
+    "product_name": "Produktname",
+    "product_code": "Produktcode",
+    "sku": "SKU",
     "price": "Preis",
-    "stock": "Bestand",
-    "status": "Status",
-    "active": "Aktiv",
-    "inactive": "Inaktiv"
-  },
-  "media": {
-    "title": "Produktmedien",
-    "upload": "Bild hochladen",
-    "delete": "Bild löschen",
-    "primary": "Als Hauptbild festlegen",
-    "error": "Medien-Upload fehlgeschlagen"
-  },
-  "validation": {
-    "name_required": "Produktname ist erforderlich",
-    "price_required": "Preis ist erforderlich",
-    "invalid_sku": "Ungültiges Artikelnummernformat",
-    "duplicate_sku": "Artikelnummer existiert bereits"
+    "sale_price": "Verkaufspreis",
+    "cost": "Kosten",
+    "stock": "Lagerbestand",
+    "in_stock": "Auf Lager",
+    "out_of_stock": "Nicht auf Lager",
+    "low_stock": "Geringer Bestand",
+    "availability": "Verfügbarkeit",
+    "available": "Verfügbar",
+    "unavailable": "Nicht verfügbar",
+    "brand": "Marke",
+    "category": "Kategorie",
+    "categories": "Kategorien",
+    "image": "Bild",
+    "images": "Bilder",
+    "main_image": "Hauptbild",
+    "gallery": "Galerie",
+    "weight": "Gewicht",
+    "dimensions": "Abmessungen",
+    "color": "Farbe",
+    "size": "Größe",
+    "material": "Material",
+    "condition": "Zustand",
+    "new": "Neu",
+    "used": "Gebraucht",
+    "refurbished": "Generalüberholt",
+    "no_products": "Keine Produkte gefunden",
+    "search_products": "Produkte suchen...",
+    "filter_by_category": "Nach Kategorie filtern",
+    "filter_by_status": "Nach Status filtern",
+    "sort_by": "Sortieren nach",
+    "sort_newest": "Neueste",
+    "sort_oldest": "Älteste",
+    "sort_price_low": "Preis: Niedrig bis Hoch",
+    "sort_price_high": "Preis: Hoch bis Niedrig",
+    "sort_name_az": "Name: A-Z",
+    "sort_name_za": "Name: Z-A"
   },
   "messages": {
-    "created": "Produkt erfolgreich erstellt",
-    "updated": "Produkt erfolgreich aktualisiert",
-    "deleted": "Produkt erfolgreich gelöscht",
-    "not_found": "Produkt nicht gefunden",
-    "cannot_delete": "Produkt kann nicht gelöscht werden",
-    "error_loading": "Fehler beim Laden der Produkte"
-  },
-  "filters": {
-    "all_products": "Alle Produkte",
-    "active_only": "Nur aktive",
-    "search_placeholder": "Produkte suchen..."
+    "product_deleted_successfully": "Product deleted successfully",
+    "please_fill_in_all_required_fields": "Please fill in all required fields",
+    "product_updated_successfully": "Product updated successfully",
+    "failed_to_load_media_library": "Failed to load media library",
+    "no_vendor_associated_with_this_product": "No vendor associated with this product",
+    "please_select_an_image_file": "Please select an image file",
+    "image_must_be_less_than_10mb": "Image must be less than 10MB",
+    "image_uploaded_successfully": "Image uploaded successfully",
+    "product_removed_from_vendor_catalog": "Product removed from vendor catalog.",
+    "please_select_a_vendor": "Please select a vendor",
+    "please_enter_a_product_title_english": "Please enter a product title (English)",
+    "product_created_successfully": "Product created successfully",
+    "please_select_a_vendor_first": "Please select a vendor first"
   }
 }