Refactor trigger_rescan to use anime_service

- Use anime_service.rescan() instead of direct trigger_rescan import
- Change Optional[Any] to Optional[Dict[str, Any]] in ConfigUpdate for better type hints
- Add ValidationError handling in ConfigUpdate.apply_to
- Update tests to match new implementation

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/server/models/config.py

@@ -246,12 +246,12 @@ class AppConfig(BaseModel):
 class ConfigUpdate(BaseModel):
     name: Optional[str] = None
     data_dir: Optional[str] = None
-    scheduler: Optional[Any] = None
-    logging: Optional[Any] = None
-    backup: Optional[Any] = None
-    nfo: Optional[Any] = None
+    scheduler: Optional[Dict[str, Any]] = None
+    logging: Optional[Dict[str, Any]] = None
+    backup: Optional[Dict[str, Any]] = None
+    nfo: Optional[Dict[str, Any]] = None
     scan_key_overrides: Optional[Dict[str, str]] = None
-    other: Optional[Any] = None
+    other: Optional[Dict[str, Any]] = None
 
     def apply_to(self, current: AppConfig) -> AppConfig:
         """Return a new AppConfig with updates applied to the current config.
@@ -271,7 +271,10 @@ class ConfigUpdate(BaseModel):
                 except json.JSONDecodeError:
                     scheduler_data = ast.literal_eval(scheduler_data)
             if isinstance(scheduler_data, dict):
-                scheduler_data = SchedulerConfig(**scheduler_data)
+                try:
+                    scheduler_data = SchedulerConfig(**scheduler_data)
+                except ValidationError:
+                    raise
             data["scheduler"] = scheduler_data.model_dump()
         if self.logging is not None:
             logging_data = self.logging