fix: notifications page crash + email code dev-mode false error

- notifications.js: EventOptions(current) referenced undefined 'Current'
  (case typo) -> ReferenceError crashed add/edit modal, page unusable
- auth.js send-verify-code: dev mode (SMTP down) deleted captcha row before
  returning code, so register always failed with '验证码无效或已过期'
  even with correct code. Keep row; it's deleted after successful verify.

public/js/pages/notifications.js

@@ -84,7 +84,7 @@ const NotificationsPage = {
   async del(id) { if(await U.confirm('确认删除？')){ try { await API.req('DELETE',`/notifications/${id}`); this.load(); } catch(ex){alert(ex.message);} } }
 };
 
-function EventOptions(current) { return ['all','ticket_created','ticket_claimed','ticket_transferred','ticket_updated'].map(e=>`<label style="cursor:pointer;font-size:12px"><input type="checkbox" value="${e}" class="ev-check" ${Current.split(',').map(s=>s.trim()).includes(e)?'checked':''}> ${EventsLabelSingle(e)}</label>`).join(''); }
+function EventOptions(current) { return ['all','ticket_created','ticket_claimed','ticket_transferred','ticket_updated'].map(e=>`<label style="cursor:pointer;font-size:12px"><input type="checkbox" value="${e}" class="ev-check" ${String(current||'').split(',').map(s=>s.trim()).includes(e)?'checked':''}> ${EventsLabelSingle(e)}</label>`).join(''); }
 function EventsLabel(v) { return v==='all'?'全部事件':v.split(',').map(s=>s.trim()).map(EventsLabelSingle).join(', '); }
 function EventsLabelSingle(e) { return {all:'全部',ticket_created:'工单创建',ticket_claimed:'工单认领',ticket_transferred:'工单转交',ticket_updated:'工单更新'}[e]||e; }
 function bindEventToggles() {