chore: 官网拆分 homepage + 关于页瘦身 + 端口 5175（当前可用状态基线）

test/stores/settingsMigration.test.ts

@@ -29,4 +29,8 @@ describe('settings migration', () => {
     const settings = normalizeAppSettings({ language: 'fr-FR' })
     expect(isAppLanguage(settings.language)).toBe(true)
   })
+  it('rejects unsupported saved themes', () => {
+    expect(normalizeAppSettings({ theme: 'invalid' }).theme).toBe('dark')
+    expect(normalizeAppSettings({ theme: 'system' }).theme).toBe('system')
+  })
 })