fix: Docker update button stuck on 'Loading settings'. Related to #1114

When system settings API fails, the catch blocks in App.tsx now call
markSystemSettingsLoadedWithDefaults() to ensure the UI doesn't stay
permanently in a loading state with disabled update buttons.

frontend-modern/src/App.tsx

@@ -52,7 +52,7 @@ import { AIChat } from './components/AI/Chat';
 import { AIStatusIndicator } from './components/AI/AIStatusIndicator';
 import { aiChatStore } from './stores/aiChat';
 import { useResourcesAsLegacy } from './hooks/useResources';
-import { updateSystemSettingsFromResponse } from './stores/systemSettings';
+import { updateSystemSettingsFromResponse, markSystemSettingsLoadedWithDefaults } from './stores/systemSettings';
 import { initKioskMode } from './utils/url';
 
 
@@ -589,6 +589,8 @@ function App() {
             setHasLoadedServerTheme(true);
           } catch (error) {
             logger.error('Failed to load theme from server', error);
+            // Ensure settings are marked as loaded so UI doesn't stay in loading state
+            markSystemSettingsLoadedWithDefaults();
           }
         }
 
@@ -637,6 +639,8 @@ function App() {
             setHasLoadedServerTheme(true);
           } catch (error) {
             logger.error('Failed to load theme from server', error);
+            // Ensure settings are marked as loaded so UI doesn't stay in loading state
+            markSystemSettingsLoadedWithDefaults();
           }
         }
 
@@ -703,7 +707,11 @@ function App() {
           // Still load system settings for other features (Docker update actions, etc.)
           SettingsAPI.getSystemSettings()
             .then((settings) => updateSystemSettingsFromResponse(settings))
-            .catch((error) => logger.warn('Failed to load system settings', error));
+            .catch((error) => {
+              logger.warn('Failed to load system settings', error);
+              // Ensure settings are marked as loaded so UI doesn't stay in loading state
+              markSystemSettingsLoadedWithDefaults();
+            });
         }
       }
     } catch (error) {

frontend-modern/src/stores/systemSettings.ts

@@ -60,6 +60,16 @@ export function areSystemSettingsLoaded(): boolean {
     return systemSettingsLoaded();
 }
 
+/**
+ * Mark settings as loaded with default values.
+ * Call this when settings fail to load but the app should continue working.
+ */
+export function markSystemSettingsLoadedWithDefaults(): void {
+    setDisableDockerUpdateActions(false);
+    setSystemSettingsLoaded(true);
+    logger.debug('System settings marked as loaded with defaults');
+}
+
 /**
  * Update the local state when settings change (e.g., from Settings page).
  */