feat: allow kgone-server.json to override the kgone server base url and soundfont base url

src/App.tsx

@@ -60,15 +60,19 @@ function App() {
       // Initialize ConfigManager first to load config.json and user settings
       await ConfigManager.instance().initialize();
 
-      // Check for kgone-server.txt (managed deployment override)
+      // Check for kgone-server.json (managed deployment override)
       try {
-        const kgoneServerResponse = await fetch(`${import.meta.env.BASE_URL}kgone-server.txt`);
+        const kgoneServerResponse = await fetch(`${import.meta.env.BASE_URL}kgone-server.json?ts=${Date.now()}`);
         const contentType = kgoneServerResponse.headers.get('Content-Type') ?? '';
-        if (kgoneServerResponse.ok && contentType.includes('text/plain')) {
-          const url = (await kgoneServerResponse.text()).trim();
-          if (url) {
-            ConfigManager.instance().setKGOneManagedByServer(url);
-            console.log('K.G.One: server-managed config loaded from kgone-server.txt, base URL:', url);
+        if (kgoneServerResponse.ok && contentType.includes('application/json')) {
+          const data = await kgoneServerResponse.json();
+          if (data.base_url) {
+            ConfigManager.instance().setKGOneManagedByServer(data.base_url);
+            console.log('K.G.One: server-managed config loaded from kgone-server.json, base URL:', data.base_url);
+          }
+          if (data.soundfont) {
+            ConfigManager.instance().setSoundfontManagedByServer(data.soundfont);
+            console.log('Soundfont: server-managed config loaded from kgone-server.json, base URL:', data.soundfont);
           }
         }
       } catch {

src/components/settings/sections/GeneralSettings.tsx

@@ -21,6 +21,7 @@ const GeneralSettings: React.FC = () => {
   const [kgoneEnabled, setKgoneEnabled] = useState<boolean>(false);
   const [kgoneBaseUrl, setKgoneBaseUrl] = useState<string>('');
   const [kgoneServerManaged, setKgoneServerManaged] = useState<boolean>(false);
+  const [soundfontServerManaged, setSoundfontServerManaged] = useState<boolean>(false);
 
   const configManager = ConfigManager.instance();
 
@@ -64,6 +65,7 @@ const GeneralSettings: React.FC = () => {
       setKgoneEnabled((configManager.get('general.kgone.enabled') as boolean) ?? false);
       setKgoneBaseUrl((configManager.get('general.kgone.base_url') as string) || '');
       setKgoneServerManaged(configManager.isKGOneServerManaged());
+      setSoundfontServerManaged(configManager.isSoundfontServerManaged());
     };
 
     loadConfig();
@@ -472,6 +474,12 @@ const GeneralSettings: React.FC = () => {
         <div className="settings-group">
           <h4>Soundfont Settings</h4>
 
+          {soundfontServerManaged && (
+            <div className="settings-help" style={{ fontSize: '12px', color: '#888', marginTop: '4px', marginBottom: '8px' }}>
+              Soundfont configuration is managed by the server (kgone-server.json). Settings are read-only.
+            </div>
+          )}
+
           <div className="settings-item">
             <label className="settings-label">
               Base URL
@@ -482,9 +490,20 @@ const GeneralSettings: React.FC = () => {
               placeholder="e.g. https://cdn.jsdelivr.net/npm/soundfont-for-samplers/FluidR3_GM/"
               value={soundfontBaseUrl}
               onChange={(e) => handleSoundfontBaseUrlChange(e.target.value)}
+              disabled={soundfontServerManaged}
             />
             <div className="settings-help" style={{ fontSize: '12px', color: '#888', marginTop: '4px' }}>
-              Changing this URL to an incompatible soundfont source may cause some instruments to sound wrong or not play.
+              Changing this URL to an incompatible soundfont source may cause some instruments to sound wrong or not play.{' '}
+              <a
+                href="#"
+                onClick={(e) => {
+                  e.preventDefault();
+                  handleSoundfontBaseUrlChange('https://cdn.jsdelivr.net/npm/soundfont-for-samplers/FluidR3_GM/');
+                }}
+                style={{ color: '#646cff', textDecoration: 'underline', cursor: 'pointer' }}
+              >
+                Restore default
+              </a>
             </div>
           </div>
         </div>
@@ -494,7 +513,7 @@ const GeneralSettings: React.FC = () => {
 
           {kgoneServerManaged && (
             <div className="settings-help" style={{ fontSize: '12px', color: '#888', marginTop: '4px', marginBottom: '8px' }}>
-              K.G.One configuration is managed by the server (kgone-server.txt). Settings are read-only.
+              K.G.One configuration is managed by the server (kgone-server.json). Settings are read-only.
             </div>
           )}
 

src/core/config/ConfigManager.ts

@@ -105,6 +105,7 @@ export class ConfigManager {
   private storage: KGConfigStorage;
   private isInitialized: boolean = false;
   private kgoneServerManaged: boolean = false;
+  private soundfontServerManaged: boolean = false;
   private defaultConfig: AppConfig | null = null;
   private changeListeners: Set<(changedKeys: string[]) => void> = new Set();
 
@@ -558,7 +559,7 @@ export class ConfigManager {
   }
 
   /**
-   * Called at startup when kgone-server.txt is found.
+   * Called at startup when kgone-server.json contains a base_url field.
    * Forces enabled=true and overrides base_url in-memory only (not persisted).
    */
   public setKGOneManagedByServer(url: string): void {
@@ -572,6 +573,20 @@ export class ConfigManager {
     return this.kgoneServerManaged;
   }
 
+  /**
+   * Called at startup when kgone-server.json contains a soundfont field.
+   * Overrides general.soundfont.base_url in-memory only (not persisted).
+   */
+  public setSoundfontManagedByServer(url: string): void {
+    this.soundfontServerManaged = true;
+    this.setInObject(this.config as Record<string, unknown>, 'general.soundfont.base_url', url);
+    this.notifyChangeListeners(['general.soundfont.base_url']);
+  }
+
+  public isSoundfontServerManaged(): boolean {
+    return this.soundfontServerManaged;
+  }
+
   /**
    * Get the default configuration
    */