refactor(arch): eliminate all cross-module model imports in service layer

Enforce MOD-025/MOD-026 rules: zero top-level cross-module model imports
remain in any service file. All 66 files migrated using deferred import
patterns (method-body, _get_model() helpers, instance-cached self._Model)
and new cross-module service methods in tenancy. Documentation updated
with Pattern 6 (deferred imports), migration plan marked complete, and
violations status reflects 84→0 service-layer violations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/cms/services/cms_features.py

@@ -157,28 +157,35 @@ class CmsFeatureProvider:
         platform_id: int,
     ) -> list[FeatureUsage]:
         from app.modules.cms.models.content_page import ContentPage
-        from app.modules.tenancy.models import Store, StorePlatform
+        from app.modules.tenancy.services.platform_service import platform_service
+        from app.modules.tenancy.services.store_service import store_service
+
+        # Get store IDs for this merchant that are on the given platform
+        merchant_stores = store_service.get_stores_by_merchant_id(db, merchant_id)
+        store_ids = []
+        for s in merchant_stores:
+            pids = platform_service.get_active_platform_ids_for_store(db, s.id)
+            if platform_id in pids:
+                store_ids.append(s.id)
+
+        if not store_ids:
+            return [
+                FeatureUsage(feature_code="cms_pages_limit", current_count=0, label="Content pages"),
+                FeatureUsage(feature_code="cms_custom_pages_limit", current_count=0, label="Custom pages"),
+            ]
 
         # Aggregate content pages across all merchant's stores on this platform
         pages_count = (
             db.query(func.count(ContentPage.id))
-            .join(Store, ContentPage.store_id == Store.id)
-            .join(StorePlatform, Store.id == StorePlatform.store_id)
-            .filter(
-                Store.merchant_id == merchant_id,
-                StorePlatform.platform_id == platform_id,
-            )
+            .filter(ContentPage.store_id.in_(store_ids))
             .scalar()
             or 0
         )
 
         custom_count = (
             db.query(func.count(ContentPage.id))
-            .join(Store, ContentPage.store_id == Store.id)
-            .join(StorePlatform, Store.id == StorePlatform.store_id)
             .filter(
-                Store.merchant_id == merchant_id,
-                StorePlatform.platform_id == platform_id,
+                ContentPage.store_id.in_(store_ids),
                 ContentPage.is_custom == True,  # noqa: E712
             )
             .scalar()

app/modules/cms/services/cms_metrics.py

@@ -147,18 +147,11 @@ class CMSMetricsProvider:
         Aggregates content management data across all stores.
         """
         from app.modules.cms.models import ContentPage, MediaFile, StoreTheme
-        from app.modules.tenancy.models import StorePlatform
+        from app.modules.tenancy.services.platform_service import platform_service
 
         try:
-            # Get all store IDs for this platform using StorePlatform junction table
-            store_ids = (
-                db.query(StorePlatform.store_id)
-                .filter(
-                    StorePlatform.platform_id == platform_id,
-                    StorePlatform.is_active == True,
-                )
-                .subquery()
-            )
+            # Get all store IDs for this platform via platform service
+            store_ids = platform_service.get_store_ids_for_platform(db, platform_id)
 
             # Content pages
             total_pages = (

app/modules/cms/services/content_page_service.py

@@ -60,22 +60,9 @@ class ContentPageService:
         Returns:
             Platform ID or None if no platform association found
         """
-        from app.modules.tenancy.models import StorePlatform
+        from app.modules.tenancy.services.platform_service import platform_service
 
-        primary_sp = (
-            db.query(StorePlatform)
-            .filter(StorePlatform.store_id == store_id, StorePlatform.is_primary.is_(True))
-            .first()
-        )
-        if primary_sp:
-            return primary_sp.platform_id
-        # Fallback: any active store_platform
-        any_sp = (
-            db.query(StorePlatform)
-            .filter(StorePlatform.store_id == store_id, StorePlatform.is_active.is_(True))
-            .first()
-        )
-        return any_sp.platform_id if any_sp else None
+        return platform_service.get_primary_platform_id_for_store(db, store_id)
 
     @staticmethod
     def resolve_platform_id_or_raise(db: Session, store_id: int) -> int:

app/modules/cms/services/store_theme_service.py

@@ -6,6 +6,8 @@ Business logic for store theme management.
 Handles theme CRUD operations, preset application, and validation.
 """
 
+from __future__ import annotations
+
 import logging
 import re
 
@@ -29,7 +31,6 @@ from app.modules.cms.services.theme_presets import (
     get_preset_preview,
 )
 from app.modules.tenancy.exceptions import StoreNotFoundException
-from app.modules.tenancy.models import Store
 
 logger = logging.getLogger(__name__)
 
@@ -67,9 +68,9 @@ class StoreThemeService:
         Raises:
             StoreNotFoundException: If store not found
         """
-        store = (
-            db.query(Store).filter(Store.store_code == store_code.upper()).first()
-        )
+        from app.modules.tenancy.services.store_service import store_service
+
+        store = store_service.get_store_by_code(db, store_code)
 
         if not store:
             self.logger.warning(f"Store not found: {store_code}")