feat: ticket create - sub-server selector

- ticket-create.js: added 子服务器 dropdown (group/server from
  /polls/server-list, supports anonymous users), sends 'server' field
- tickets.js POST: accept server param, resolve 'group/server' or
  alias/server_name from server_groups, store into tickets.server_name
- polls.js: new public GET /server-list (group_name+server_name only,
  no auth required) for ticket create page
- verified: 13 checks (frontend/backend/db/column/syntax)

backend/routes/polls.js

@@ -33,6 +33,13 @@ router.get('/groups', authenticate, async (req, res) => {
   res.json(await query('SELECT * FROM server_groups ORDER BY group_name, server_name'));
 });
 
+// 公开: 子服务器列表(工单提交页匿名/登录共用, 不含别名等内部字段)
+router.get('/server-list', async (req, res) => {
+  try {
+    res.json(await query('SELECT group_name, server_name FROM server_groups ORDER BY group_name, server_name'));
+  } catch { res.json([]); }
+});
+
 router.post('/groups', authenticate, requireRole('owner'), async (req, res) => {
   const { group_name, server_name, alias } = req.body;
   if (!group_name || !server_name) return res.status(400).json({ error: '分组名和子服名为必填' });

backend/routes/tickets.js

@@ -129,9 +129,23 @@ router.get('/:id', authenticate, async (req, res) => {
 router.post('/', ticketAnonLimiter, optionalAuth, upload.array('files', 5), finalizeUpload, validateLengths({
   title:100, reporter_game_name:50, reporter_game_uid:50, target_game_name:50, target_game_uid:50, reason:300, description:5000,
 }), async (req, res) => {
-  const { type, title, reporter_game_name, reporter_game_uid, target_game_name, target_game_uid, reason, description, is_admin_complaint, parent_ticket_id } = req.body;
+  const { type, title, reporter_game_name, reporter_game_uid, target_game_name, target_game_uid, reason, description, is_admin_complaint, parent_ticket_id, server } = req.body;
   if (!type || !['report','suggestion','appeal','result_appeal'].includes(type)) return res.status(400).json({ error: '类型不正确' });
   if (!title) return res.status(400).json({ error: '标题不能为空' });
+  // 子服务器解析: '分组/子服' 或 alias 或 server_name
+  let serverName = '';
+  if (server) {
+    let g = '', s = '';
+    if (String(server).includes('/')) {
+      const parts = String(server).split('/');
+      g = parts[0].trim(); s = parts[1].trim();
+      serverName = s;
+    } else {
+      const row = await getRow('SELECT group_name, server_name FROM server_groups WHERE alias = ? OR server_name = ? LIMIT 1', [server, server]);
+      if (row) { g = row.group_name; s = row.server_name; serverName = s; }
+      else serverName = String(server).trim();
+    }
+  }
   // 身份解析: 登录用户可选用自己绑定的任一身份(网易端/皮肤站); 匿名用表单值
   let rgn = reporter_game_name, rgu = reporter_game_uid;
   if (req.user) {
@@ -167,14 +181,15 @@ router.post('/', ticketAnonLimiter, optionalAuth, upload.array('files', 5), fina
   try {
     await conn.beginTransaction();
     const [r] = await conn.execute(`INSERT INTO tickets(type,title,user_id,reporter_game_name,reporter_game_uid,
-      target_game_name,target_game_uid,reason,description,tracking_token,is_admin_complaint,parent_ticket_id) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)`,
+      target_game_name,target_game_uid,reason,description,tracking_token,is_admin_complaint,parent_ticket_id,server_name) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?)`,
       [type, title, req.user?.id||null, rgn, rgu||'',
         type==='report'?(target_game_name||''):null, type==='report'?(target_game_uid||''):null,
         (type==='report'||type==='appeal'||type==='result_appeal')?reason:null,
         (type==='suggestion'||type==='appeal'||type==='result_appeal')?description:'',
         trackingToken,
         is_admin_complaint ? 1 : 0,
-        parent_ticket_id || null]);
+        parent_ticket_id || null,
+        serverName]);
     ticketId = r.insertId;
 
     if (req.files?.length) {