Remove redundant Save All button from hub settings page.

Each settings tab already has its own save action; keep reload only.

Co-authored-by: Cursor <cursoragent@cursor.com>

manual_trading_hub/static/app.js

@@ -4634,10 +4634,6 @@
     }
   }
 
-  async function saveSettings() {
-    await saveSettingsSection("all", { label: "全部设置" });
-  }
-
   document.getElementById("btn-logout").onclick = async () => {
     try {
       await fetch("/api/auth/logout", { method: "POST" });
@@ -4654,7 +4650,6 @@
     }
   };
   document.getElementById("btn-close-all").onclick = closeAll;
-  document.getElementById("btn-settings-save").onclick = saveSettings;
   document.getElementById("btn-settings-reload").onclick = loadSettingsUI;
   document.getElementById("btn-settings-add").onclick = () => {
     const data = settingsCache || { exchanges: [] };