fix: HIGH+MEDIUM bugs from full audit - listen error, JWT, upload, mailer, webhook

backend/routes/tickets.js

@@ -185,6 +185,7 @@ router.put('/:id', authenticate, requireRole('owner','admin'), async (req, res)
   const fields = {};
   if (req.body.status) fields.status = req.body.status;
   if (req.body.priority) fields.priority = req.body.priority;
+  if (req.body.priority && !['low','medium','high','urgent'].includes(req.body.priority)) return res.status(400).json({ error: '无效的优先级' });
   if (req.body.claim_note !== undefined) fields.claim_note = req.body.claim_note;
   if (!Object.keys(fields).length) return res.status(400).json({ error: '无更新内容' });
   const sets = Object.keys(fields).map(k => `${k} = ?`).join(', ');