Fix double POST on open position in embed shell mode.

Embed capture-phase form handler and allowManualOrderSubmit both submitted /add_order; skip custom forms and use a single fetch reload path.

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

embed_templates/embed_boot_scripts.html

@@ -889,6 +889,10 @@ function cancelExchangeTpsl(orderId, role){
 
 function allowManualOrderSubmit(form){
     form.dataset.rrOk = "1";
+    if(document.body && document.body.getAttribute("data-embed-shell") === "1" && window.InstanceEmbed && window.InstanceEmbed.postFormAndReload){
+        window.InstanceEmbed.postFormAndReload(form, "开仓提交中…");
+        return;
+    }
     if(window.FormSubmitGuard){
         if(FormSubmitGuard.isLocked(form)){
             FormSubmitGuard.setSubmitLabel(form, "开仓提交中…");