refactor(settings): invert sync logic from whitelist to blacklist

Replace _SYNC_KEYS (37 keys) with _NO_SYNC_KEYS (5 keys) in SettingsHandler.
New settings automatically sync to frontend unless explicitly excluded.

Changes:
- SettingsHandler now syncs all settings except those in _NO_SYNC_KEYS
- Added keys() method to SettingsManager for iteration
- Updated tests to use new behavior

Benefits:
- No more missing keys when adding new settings
- Reduced maintenance burden
- Explicit exclusions for sensitive/internal settings only

Fixes: #86

py/routes/handlers/misc_handlers.py

@@ -220,45 +220,17 @@ class HealthCheckHandler:
 class SettingsHandler:
     """Sync settings between backend and frontend."""
 
-    _SYNC_KEYS = (
+    # Settings keys that should NOT be synced to frontend.
-        "civitai_api_key",
+    # All other settings are synced by default.
-        "default_lora_root",
+    _NO_SYNC_KEYS = frozenset({
-        "default_checkpoint_root",
+        # Internal/performance settings (not used by frontend)
-        "default_unet_root",
+        "hash_chunk_size_mb",
-        "default_embedding_root",
+        "download_stall_timeout_seconds",
-        "base_model_path_mappings",
+        # Complex internal structures retrieved via separate endpoints
-        "download_path_templates",
+        "folder_paths",
-        "enable_metadata_archive_db",
+        "libraries",
-        "language",
+        "active_library",
-        "use_portable_settings",
+    })
-        "onboarding_completed",
-        "dismissed_banners",
-        "proxy_enabled",
-        "proxy_type",
-        "proxy_host",
-        "proxy_port",
-        "proxy_username",
-        "proxy_password",
-        "example_images_path",
-        "optimize_example_images",
-        "auto_download_example_images",
-        "blur_mature_content",
-        "autoplay_on_hover",
-        "display_density",
-        "card_info_display",
-        "show_folder_sidebar",
-        "include_trigger_words",
-        "show_only_sfw",
-        "compact_mode",
-        "priority_tags",
-        "model_card_footer_action",
-        "model_name_display",
-        "update_flag_strategy",
-        "auto_organize_exclusions",
-        "metadata_refresh_skip_paths",
-        "filter_presets",
-        "hide_early_access_updates",
-    )
 
     _PROXY_KEYS = {
         "proxy_enabled",
@@ -305,10 +277,12 @@ class SettingsHandler:
     async def get_settings(self, request: web.Request) -> web.Response:
         try:
             response_data = {}
-            for key in self._SYNC_KEYS:
+            # Sync all settings except those in _NO_SYNC_KEYS
-                value = self._settings.get(key)
+            for key in self._settings.keys():
-                if value is not None:
+                if key not in self._NO_SYNC_KEYS:
-                    response_data[key] = value
+                    value = self._settings.get(key)
+                    if value is not None:
+                        response_data[key] = value
             settings_file = getattr(self._settings, "settings_file", None)
             if settings_file:
                 response_data["settings_file"] = settings_file

py/services/settings_manager.py

@@ -994,6 +994,10 @@ class SettingsManager:
             self._save_settings()
             logger.info(f"Deleted setting: {key}")
 
+    def keys(self) -> Iterable[str]:
+        """Return all setting keys."""
+        return self.settings.keys()
+
     def _prepare_portable_switch(self, use_portable: bool) -> None:
         """Prepare switching the settings storage location."""
 

tests/routes/__snapshots__/test_api_snapshots.ambr

@@ -26,6 +26,7 @@
     'settings': dict({
       'civitai_api_key': 'test-key',
       'language': 'en',
+      'theme': 'dark',
     }),
     'success': True,
   })

tests/routes/test_api_snapshots.py

@@ -45,6 +45,9 @@ class DummySettings:
     def set(self, key, value):
         self.data[key] = value
 
+    def keys(self):
+        return self.data.keys()
+
 
 async def noop_async(*_args, **_kwargs):
     """No-op async function."""

tests/routes/test_misc_routes.py

@@ -44,6 +44,9 @@ class DummySettings:
     def delete(self, key):
         self.data.pop(key, None)
 
+    def keys(self):
+        return self.data.keys()
+
 
 class DummyDownloader:
     def __init__(self):
@@ -62,8 +65,14 @@ async def dummy_downloader_factory():
 
 
 @pytest.mark.asyncio
-async def test_get_settings_filters_sync_keys():
+async def test_get_settings_excludes_no_sync_keys():
-    settings_service = DummySettings({"civitai_api_key": "abc", "extraneous": "value"})
+    """Verify that settings in _NO_SYNC_KEYS are not synced, but others are."""
+    settings_service = DummySettings({
+        "civitai_api_key": "abc",
+        "hash_chunk_size_mb": 10,
+        "folder_paths": {"/some/path"},
+        "regular_setting": "value",
+    })
     handler = SettingsHandler(
         settings_service=settings_service,
         metadata_provider_updater=noop_async,
@@ -74,7 +83,12 @@ async def test_get_settings_filters_sync_keys():
     payload = json.loads(response.text)
 
     assert payload["success"] is True
-    assert payload["settings"] == {"civitai_api_key": "abc"}
+    # Regular settings should be synced
+    assert payload["settings"]["civitai_api_key"] == "abc"
+    assert payload["settings"]["regular_setting"] == "value"
+    # _NO_SYNC_KEYS should not be synced
+    assert "hash_chunk_size_mb" not in payload["settings"]
+    assert "folder_paths" not in payload["settings"]
 
 
 @pytest.mark.asyncio