introduce lint for client

Resolve #7998

packages/client/src/pages/settings/index.vue

@@ -217,6 +217,7 @@ export default defineComponent({
 			if (page.value.startsWith('registry/value/system/')) {
 				return defineAsyncComponent(() => import('./registry.value.vue'));
 			}
+			return null;
 		});
 
 		watch(component, () => {

packages/client/src/pages/settings/theme.vue

@@ -148,7 +148,7 @@ export default defineComponent({
 		const themesCount = installedThemes.value.length;
 
 		watch(syncDeviceDarkMode, () => {
-			if (syncDeviceDarkMode) {
+			if (syncDeviceDarkMode.value) {
 				defaultStore.set('darkMode', isDeviceDarkmode());
 			}
 		});