refactor: update module imports to use module locations

Update all module files to import from canonical module locations
instead of legacy re-export files:
- checkout, orders, customers routes: use module schemas
- catalog, marketplace schemas: use inventory module schemas
- marketplace, customers, inventory, analytics services: use module models

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

app/modules/inventory/locales/de.json

@@ -0,0 +1 @@
+{}

app/modules/inventory/locales/en.json

@@ -0,0 +1 @@
+{}

app/modules/inventory/locales/fr.json

@@ -0,0 +1 @@
+{}

app/modules/inventory/locales/lu.json

@@ -0,0 +1 @@
+{}

app/modules/inventory/routes/api/__init__.py

@@ -0,0 +1,4 @@
+# Routes will be migrated here from legacy locations
+# TODO: Move actual route implementations from app/api/v1/
+
+__all__ = []

app/modules/inventory/routes/pages/__init__.py

@@ -0,0 +1,4 @@
+# Page routes will be added here
+# TODO: Add HTML page routes for admin/vendor dashboards
+
+__all__ = []

app/modules/inventory/services/inventory_transaction_service.py

@@ -14,7 +14,7 @@ from sqlalchemy.orm import Session
 from app.exceptions import OrderNotFoundException, ProductNotFoundException
 from app.modules.inventory.models.inventory import Inventory
 from app.modules.inventory.models.inventory_transaction import InventoryTransaction
-from models.database.order import Order
+from app.modules.orders.models import Order
 from models.database.product import Product
 
 logger = logging.getLogger(__name__)