refactor(lora-pool-widget): adopt DOM widget value persistence best practices

- Replace custom onSetValue with ComfyUI's built-in widget.callback
- Remove widget.updateConfig, set widget.value directly
- Add isRestoring flag to break callback → watch → refreshPreview loop
- Update ComponentWidget types with callback and deprecate old methods

Refs: docs/dom-widgets/value-persistence-best-practices.md

vue-widgets/src/main.ts

@@ -90,9 +90,8 @@ function createLoraPoolWidget(node) {
       },
       setValue(v: LoraPoolConfig | LegacyLoraPoolConfig) {
         internalValue = v
-        if (typeof widget.onSetValue === 'function') {
-          widget.onSetValue(v)
-        }
+        // ComfyUI automatically calls widget.callback after setValue
+        // No need for custom onSetValue mechanism
       },
       serialize: true,
       // Per dev guide: providing getMinHeight via options allows the system to
@@ -103,10 +102,6 @@ function createLoraPoolWidget(node) {
     }
   )
 
-  widget.updateConfig = (v: LoraPoolConfig) => {
-    internalValue = v
-  }
-
   const vueApp = createApp(LoraPoolWidget, {
     widget,
     node