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()