feat: ticket create - identity-only for logged-in users

- logged-in users: identity dropdown shown when >=1 identity exists,
  game name input hidden (identity carries the submitter); required
  removed from hidden field
- no identity: fall back to showing the game name input
- anonymous: unchanged, only the input field
- submit: identity selection still overrides reporter name/uid

public/js/pages/ticket-create.js

@@ -34,9 +34,22 @@ const TicketCreate = {
       API.get('/auth/identities').then(list => {
         this.identities = list || [];
         const sel = container.querySelector('#identity-select');
-        if (sel && this.identities.length > 1) {
-          sel.innerHTML = this.identities.map((it, i) => `<option value="${i}">${U.esc(it.source)} — ${U.esc(it.game_name)}</option>`).join('');
-          sel.closest('.form-group').classList.remove('hidden');
+        const nameGroup = container.querySelector('#reporter-name-group');
+        if (sel) {
+          if (this.identities.length > 0) {
+            // 有身份: 显示身份选择, 隐藏游戏名输入框(身份即代表提交者)
+            sel.innerHTML = this.identities.map((it, i) => `<option value="${i}">${U.esc(it.source)} — ${U.esc(it.game_name)}</option>`).join('');
+            sel.closest('.form-group').classList.remove('hidden');
+            if (nameGroup) {
+              nameGroup.classList.add('hidden');
+              const inp = nameGroup.querySelector('input[name="reporter_game_name"]');
+              if (inp) inp.required = false; // 隐藏字段不再参与原生必填校验
+            }
+          } else {
+            // 无身份: 保留游戏名输入框兜底
+            sel.closest('.form-group').classList.add('hidden');
+            if (nameGroup) nameGroup.classList.remove('hidden');
+          }
         }
       }).catch(() => {});
     }
@@ -82,11 +95,11 @@ const TicketCreate = {
             </div>
 
             ${user ? `<div class="form-group hidden" id="identity-group">
-              <label>使用身份</label>
+              <label>使用身份 *</label>
               <select id="identity-select"></select>
             </div>` : ''}
 
-            <div class="form-group">
+            <div class="form-group" id="reporter-name-group">
               <label>您的游戏名称 *</label>
               <input name="reporter_game_name" required placeholder="Minecraft ID" value="${U.esc(prefill?.game_name || user?.game_name || '')}" ${prefill?.game_name ? 'readonly' : ''}>
             </div>