fix: wrap HTTP_SERVER_GET_STATUS response in IpcResult envelope

The HTTP_SERVER_GET_STATUS handler returned a raw { running, port } object
while all other HTTP server handlers (start, stop) return { success, data }.
invokeIpcWithResult() in the preload expects the IpcResult<T> envelope and
treats a missing success field as failure, throwing 'Unknown error'.

This caused an unhandled promise rejection every time the Settings page
opened, because GeneralSection calls api.httpServer.getStatus() on mount.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main/index.ts

@@ -310,7 +310,7 @@ function initializeServices(): void {
   });
 
   ipcMain.handle(HTTP_SERVER_GET_STATUS, () => {
-    return { running: httpServer.isRunning(), port: httpServer.getPort() };
+    return { success: true, data: { running: httpServer.isRunning(), port: httpServer.getPort() } };
   });
 
   // Forward SSH state changes to renderer and HTTP SSE clients