fix: resolve all remaining legacy import issues

- Update models/database/__init__.py to import from module locations
- Update models/schema/__init__.py to remove deleted modules
- Update models/__init__.py to import Inventory from module
- Remove duplicate AdminNotification from models/database/admin.py
- Fix monitoring module to import AdminNotification from messaging
- Update stats schema imports in admin/vendor API
- Update notification schema imports
- Add order_item_exception.py schema to orders module
- Fix app/api/v1/__init__.py to use storefront instead of shop
- Add cms_admin_pages import to main.py
- Fix password_reset_token imports
- Fix AdminNotification test imports

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

models/schema/__init__.py

@@ -1,18 +1,22 @@
 # models/schema/__init__.py
-"""API models package - Pydantic models for request/response validation."""
+"""API models package - Pydantic models for request/response validation.
 
-# Import API model modules
+Note: Many schemas have been migrated to their respective modules:
+- Customer schemas: app.modules.customers.schemas
+- Order schemas: app.modules.orders.schemas
+- Inventory schemas: app.modules.inventory.schemas
+- Message schemas: app.modules.messaging.schemas
+- Cart schemas: app.modules.cart.schemas
+"""
+
+# Import API model modules that remain in legacy location
 from . import (
     auth,
     base,
     email,
-    inventory,
-    invoice,
     marketplace_import_job,
     marketplace_product,
-    message,
     onboarding,
-    stats,
     vendor,
 )
 
@@ -23,12 +27,8 @@ __all__ = [
     "base",
     "auth",
     "email",
-    "invoice",
     "marketplace_product",
-    "message",
-    "inventory",
     "onboarding",
     "vendor",
     "marketplace_import_job",
-    "stats",
 ]