fix: address code review — unused import, silent except, gallery cache

- Remove unused `patch` import from test_output_dir.py
- Add debug log message to ImportError handler instead of bare pass
- Invalidate gallery file listing cache alongside output dir cache
  when the user changes gallery_root_path in settings

py/api/__init__.py

@@ -482,7 +482,9 @@ class PromptManagerAPI(
                         f"Configured directory does not exist: {GalleryConfig.MONITORING_DIRECTORIES[0]}"
                     )
         except ImportError:
-            pass
+            self.logger.debug(
+                "GalleryConfig not available, skipping configured directory check"
+            )
 
         current_file = Path(__file__).resolve()
         self.logger.debug(f"Starting ComfyUI output search from: {current_file}")

py/api/admin.py

@@ -448,8 +448,10 @@ class AdminRoutesMixin:
                         GalleryConfig.MONITORING_DIRECTORIES = [new_path]
                     else:
                         GalleryConfig.MONITORING_DIRECTORIES = []
-                    # Invalidate cached output dir so next lookup uses new config
+                    # Invalidate caches so next lookup uses new config
                     self._cached_output_dir = None
+                    self._gallery_cache = None
+                    self._gallery_cache_time = 0
                     restart_required = True
 
             # Save to config file for persistence