fix: hide the background updater console window on Windows

.changeset/fix-windows-update-console-flash.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Keep automatic background updates from flashing a console window on Windows.

apps/kimi-code/src/cli/update/preflight.ts

@@ -607,6 +607,10 @@ async function startBackgroundInstall(
       detached: true,
       stdio: 'ignore',
       shell: platform === 'win32' ? true : undefined,
+      // On Windows a detached child gets its own console window; with shell:true
+      // that window would flash during a passive background update. Hide it so
+      // the silent updater stays silent.
+      windowsHide: platform === 'win32' ? true : undefined,
     });
     child.once('error', () => { finish(false); });
     child.once('exit', (code) => { finish(code === 0); });

apps/kimi-code/test/cli/update/preflight.test.ts

@@ -600,6 +600,27 @@ describe('runUpdatePreflight', () => {
     }));
   });
 
+  it('win32 background auto-update hides the console window', async () => {
+    mocks.readUpdateCache.mockResolvedValue(cacheWith('0.5.0'));
+    mocks.readUpdateInstallState.mockResolvedValue(installState());
+    mocks.refreshUpdateCache.mockResolvedValue(cacheWith('0.5.0'));
+    mocks.detectInstallSource.mockResolvedValue('npm-global');
+    mockSpawnExit(0);
+    const originalPlatform = process.platform;
+    Object.defineProperty(process, 'platform', { value: 'win32' });
+    try {
+      const { options } = captureOutput();
+      await expect(runUpdatePreflight('0.4.0', options)).resolves.toBe('continue');
+      expect(mocks.spawn).toHaveBeenCalledWith(
+        'npm.cmd',
+        ['install', '-g', '@moonshot-ai/kimi-code@0.5.0'],
+        { detached: true, stdio: 'ignore', shell: true, windowsHide: true },
+      );
+    } finally {
+      Object.defineProperty(process, 'platform', { value: originalPlatform });
+    }
+  });
+
   it('tracks and logs successful background update installs', async () => {
     mocks.readUpdateCache.mockResolvedValue(cacheWith('0.5.0'));
     mocks.readUpdateInstallState.mockResolvedValue(installState());