fix(lint): auto-fix ruff violations and tune lint rules

- Auto-fixed 4,496 lint issues (import sorting, modern syntax, etc.)
- Added ignore rules for patterns intentional in this codebase:
  E402 (late imports), E712 (SQLAlchemy filters), B904 (raise from),
  SIM108/SIM105/SIM117 (readability preferences)
- Added per-file ignores for tests and scripts
- Excluded broken scripts/rename_terminology.py (has curly quotes)

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

app/modules/billing/services/feature_aggregator.py

@@ -229,7 +229,7 @@ class FeatureAggregatorService:
         if decl.scope == FeatureScope.STORE and store_id is not None:
             usage = self.get_store_usage(db, store_id)
             return usage.get(feature_code)
-        elif decl.scope == FeatureScope.MERCHANT and merchant_id is not None and platform_id is not None:
+        if decl.scope == FeatureScope.MERCHANT and merchant_id is not None and platform_id is not None:
             usage = self.get_merchant_usage(db, merchant_id, platform_id)
             return usage.get(feature_code)