fix: resolve pylint and type-checking issues

- Fix return type annotation in SetupRedirectMiddleware.dispatch() to use Response instead of RedirectResponse
- Replace broad 'except Exception' with specific exception types (FileNotFoundError, ValueError, OSError, etc.)
- Rename AppConfig.validate() to validate_config() to avoid shadowing BaseModel.validate()
- Fix ValidationResult.errors field to use List[str] with default_factory
- Add pylint disable comments for intentional broad exception catches during shutdown
- Rename lifespan parameter to _application to indicate unused variable
- Update all callers to use new validate_config() method name

src/server/fastapi_app.py

@@ -43,8 +43,13 @@ from src.server.services.websocket_service import get_websocket_service
 
 
 @asynccontextmanager
-async def lifespan(app: FastAPI):
-    """Manage application lifespan (startup and shutdown)."""
+async def lifespan(_application: FastAPI):
+    """Manage application lifespan (startup and shutdown).
+    
+    Args:
+        _application: The FastAPI application instance (unused but required
+            by the lifespan protocol).
+    """
     # Setup logging first with DEBUG level
     logger = setup_logging(log_level="DEBUG")
     
@@ -72,8 +77,11 @@ async def lifespan(app: FastAPI):
             )
             
             # Sync anime_directory from config.json to settings
-            if config.other and config.other.get("anime_directory"):
-                settings.anime_directory = str(config.other["anime_directory"])
+            # config.other is Dict[str, object] - pylint doesn't infer this
+            other_settings = dict(config.other) if config.other else {}
+            if other_settings.get("anime_directory"):
+                anime_dir = other_settings["anime_directory"]
+                settings.anime_directory = str(anime_dir)
                 logger.info(
                     "Loaded anime_directory from config: %s",
                     settings.anime_directory
@@ -82,7 +90,7 @@ async def lifespan(app: FastAPI):
                 logger.debug(
                     "anime_directory not found in config.other"
                 )
-        except Exception as e:
+        except (OSError, ValueError, KeyError) as e:
             logger.warning("Failed to load config from config.json: %s", e)
 
         # Initialize progress service with event subscription
@@ -131,7 +139,7 @@ async def lifespan(app: FastAPI):
                     "Download service initialization skipped - "
                     "anime directory not configured"
                 )
-        except Exception as e:
+        except (OSError, RuntimeError, ValueError) as e:
             logger.warning("Failed to initialize download service: %s", e)
             # Continue startup - download service can be initialized later
 
@@ -152,12 +160,14 @@ async def lifespan(app: FastAPI):
     
     # Shutdown download service and its thread pool
     try:
-        from src.server.services.download_service import _download_service_instance
+        from src.server.services.download_service import (  # noqa: E501
+            _download_service_instance,
+        )
         if _download_service_instance is not None:
             logger.info("Stopping download service...")
             await _download_service_instance.stop()
             logger.info("Download service stopped successfully")
-    except Exception as e:
+    except Exception as e:  # pylint: disable=broad-exception-caught
         logger.error("Error stopping download service: %s", e, exc_info=True)
     
     # Close database connections
@@ -165,7 +175,7 @@ async def lifespan(app: FastAPI):
         from src.server.database.connection import close_db
         await close_db()
         logger.info("Database connections closed")
-    except Exception as e:
+    except Exception as e:  # pylint: disable=broad-exception-caught
         logger.error("Error closing database: %s", e, exc_info=True)
     
     logger.info("FastAPI application shutdown complete")

src/server/middleware/setup_redirect.py

@@ -11,7 +11,7 @@ from typing import Callable
 
 from fastapi import Request
 from starlette.middleware.base import BaseHTTPMiddleware
-from starlette.responses import RedirectResponse
+from starlette.responses import RedirectResponse, Response
 from starlette.types import ASGIApp
 
 from src.server.services.auth_service import auth_service
@@ -91,11 +91,11 @@ class SetupRedirectMiddleware(BaseHTTPMiddleware):
             config = config_service.load_config()
             
             # Validate the loaded config
-            validation = config.validate()
+            validation = config.validate_config()
             if not validation.valid:
                 return True
                 
-        except Exception:
+        except (FileNotFoundError, ValueError, OSError, AttributeError):
             # If we can't load or validate config, setup is needed
             return True
         
@@ -103,7 +103,7 @@ class SetupRedirectMiddleware(BaseHTTPMiddleware):
     
     async def dispatch(
         self, request: Request, call_next: Callable
-    ) -> RedirectResponse:
+    ) -> Response:
         """Process the request and redirect to setup if needed.
         
         Args:

src/server/models/config.py

@@ -58,8 +58,9 @@ class ValidationResult(BaseModel):
     """Result of a configuration validation attempt."""
 
     valid: bool = Field(..., description="Whether the configuration is valid")
-    errors: Optional[List[str]] = Field(
-        default_factory=list, description="List of validation error messages"
+    errors: List[str] = Field(
+        default_factory=lambda: [],
+        description="List of validation error messages"
     )
 
 
@@ -71,14 +72,16 @@ class AppConfig(BaseModel):
 
     name: str = Field(default="Aniworld", description="Application name")
     data_dir: str = Field(default="data", description="Base data directory")
-    scheduler: SchedulerConfig = Field(default_factory=SchedulerConfig)
+    scheduler: SchedulerConfig = Field(
+        default_factory=SchedulerConfig
+    )
     logging: LoggingConfig = Field(default_factory=LoggingConfig)
     backup: BackupConfig = Field(default_factory=BackupConfig)
     other: Dict[str, object] = Field(
         default_factory=dict, description="Arbitrary other settings"
     )
 
-    def validate(self) -> ValidationResult:
+    def validate_config(self) -> ValidationResult:
         """Perform light-weight validation and return a ValidationResult.
 
         This method intentionally avoids performing IO (no filesystem checks)
@@ -98,7 +101,8 @@ class AppConfig(BaseModel):
                 errors.append(msg)
 
         # backup.path must be set when backups are enabled
-        if self.backup.enabled and (not self.backup.path):
+        backup_data = self.model_dump().get("backup", {})
+        if backup_data.get("enabled") and not backup_data.get("path"):
             errors.append(
                 "backup.path must be set when backups.enabled is true"
             )

src/server/services/config_service.py

@@ -90,7 +90,7 @@ class ConfigService:
             config = AppConfig(**data)
             
             # Validate configuration
-            validation = config.validate()
+            validation = config.validate_config()
             if not validation.valid:
                 errors = ', '.join(validation.errors or [])
                 raise ConfigValidationError(
@@ -123,7 +123,7 @@ class ConfigService:
             ConfigValidationError: If config validation fails
         """
         # Validate before saving
-        validation = config.validate()
+        validation = config.validate_config()
         if not validation.valid:
             errors = ', '.join(validation.errors or [])
             raise ConfigValidationError(
@@ -180,7 +180,7 @@ class ConfigService:
         Returns:
             ValidationResult: Validation result with errors if any
         """
-        return config.validate()
+        return config.validate_config()
     
     def create_backup(self, name: Optional[str] = None) -> Path:
         """Create backup of current configuration.

tests/unit/test_config_models.py

@@ -44,12 +44,12 @@ def test_appconfig_and_config_update_apply_to():
 def test_backup_and_validation():
     cfg = AppConfig()
     # default backups disabled -> valid
-    res: ValidationResult = cfg.validate()
+    res: ValidationResult = cfg.validate_config()
     assert res.valid is True
 
     # enable backups but leave path empty -> invalid
     cfg.backup.enabled = True
     cfg.backup.path = ""
-    res2 = cfg.validate()
+    res2 = cfg.validate_config()
     assert res2.valid is False
     assert any("backup.path" in e for e in res2.errors)