fix: 覆盖层页面添加新增按钮，支持空白新建

internal/web/ui.go

@@ -4144,7 +4144,10 @@ func (u *UI) pageAssetOverlays(w http.ResponseWriter, r *http.Request) {
         }
     }
     if newMode {
-        data.AssetOverlayEditing = data.AssetOverlay != nil
+        if data.AssetOverlay == nil {
+            data.AssetOverlay = &service.ConfigOverlayAsset{Name: "", Raw: map[string]any{}}
+        }
+        data.AssetOverlayEditing = true
     } else {
         data.AssetOverlayEditing = editMode && data.AssetOverlay != nil && !data.AssetOverlay.ReadOnly
     }

internal/web/ui/templates/asset_overlays.html

@@ -7,6 +7,7 @@
       <div class="form-hint">标准调试参数应作为基线，复制后再做定制化修改。</div>
     </div>
     <div class="actions compact">
+      <a class="btn secondary" href="/assets/overlays?new=1">{{icon "apply"}}<span>新增调试参数</span></a>
       {{if .AssetOverlay}}
         {{if .AssetOverlay.ReadOnly}}
         <form method="post" action="/assets/overlays/{{.AssetOverlay.Name}}/clone">