fix: add required DebugMode field to API request body

API returns "参数DebugMode未找到" without it, causing all calls to fail.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: boomzero

messages.html

@@ -476,7 +476,8 @@ <h5 class="mb-0 flex-grow-1" id="thread-title">与 … 的对话</h5>
         body: JSON.stringify({
             Authentication: { SessionID: currentUser.phpsessid, Username: currentUser.username },
             Data: data,
-            Version: WEBUI_VERSION
+            Version: WEBUI_VERSION,
+            DebugMode: false
         })
     });
     if (!res.ok) throw new Error('HTTP ' + res.status);