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/payments/services/gateway_service.py

@@ -97,13 +97,11 @@ class BaseGateway(ABC):
     @abstractmethod
     def code(self) -> str:
         """Gateway code identifier."""
-        pass
 
     @property
     @abstractmethod
     def name(self) -> str:
         """Gateway display name."""
-        pass
 
     @abstractmethod
     async def process_payment(
@@ -114,7 +112,6 @@ class BaseGateway(ABC):
         **kwargs: Any,
     ) -> dict[str, Any]:
         """Process a payment."""
-        pass
 
     @abstractmethod
     async def refund(
@@ -123,7 +120,6 @@ class BaseGateway(ABC):
         amount: int | None = None,
     ) -> dict[str, Any]:
         """Issue a refund."""
-        pass
 
     async def health_check(self) -> bool:
         """Check if gateway is operational."""