修复：管理操作下拉框添加警告和查看私聊选项

- input-bar 下拉新增 '⚠️ 警告' 和 '🔍 查看私聊' 选项
- executeAdminAction 增加 warn/whispers 的交互逻辑
- 修正 warn 参数名匹配后端（username/reason）
- 所有操作项添加 emoji 图标提升辨识度

resources/views/chat/partials/input-bar.blade.php

@@ -63,17 +63,23 @@
                 <select id="admin-action-select"
                     style="font-size: 11px; padding: 1px 2px; border: 1px solid #8ab; border-radius: 2px; color: #c00;">
                     <option value="">管理操作 ▾</option>
+                    @if ($user->user_level >= $levelWarn || $room->master == $user->username)
+                        <option value="warn">⚠️ 警告</option>
+                    @endif
                     @if ($user->user_level >= $levelKick || $room->master == $user->username)
-                        <option value="kick">踢出房间</option>
+                        <option value="kick">👢 踢出房间</option>
                     @endif
                     @if ($user->user_level >= $levelMute || $room->master == $user->username)
-                        <option value="mute">禁言</option>
+                        <option value="mute">🔇 禁言</option>
                     @endif
                     @if ($user->user_level >= $levelBan)
-                        <option value="ban">封号</option>
+                        <option value="ban">🚫 封号</option>
                     @endif
                     @if ($user->user_level >= $levelBanip)
-                        <option value="banip">封IP</option>
+                        <option value="banip">🔒 封IP</option>
+                    @endif
+                    @if ($user->user_level >= $levelKick || $room->master == $user->username)
+                        <option value="whispers">🔍 查看私聊</option>
                     @endif
                 </select>
                 <button type="button" onclick="executeAdminAction()"