- New config/notify_store.go: persistent notification config (notify.json)
- New API: GET/PUT /api/notify/config, POST /api/notify/test-feishu, POST /api/notify/test-email
- New Vue page: NotifyConfig.vue with feishu webhook and SMTP settings
- Updated cron/init to read from persistent store instead of env vars
- Password masked as ******** in API responses, preserved on updates