refactor: use placeholder to display deserialized values instead of modifying options

Simplified the approach to show deserialized workflow values that are not in
the current options list. Instead of adding missing values to the options array,
we now display them as the placeholder text. This is cleaner, avoids array
manipulation, and addresses performance concerns from code review.

src/renderer/extensions/vueNodes/widgets/components/WidgetSelectDefault.vue

@@ -3,6 +3,7 @@
     <Select
       v-model="localValue"
       :options="selectOptions"
+      :placeholder="selectPlaceholder"
       v-bind="combinedProps"
       :class="cn(WidgetInputBaseClass, 'w-full text-xs')"
       :aria-label="widget.name"
@@ -64,9 +65,27 @@ const selectOptions = computed(() => {
   const options = props.widget.options
 
   if (options?.values && Array.isArray(options.values)) {
-    return ensureValueInOptions(options.values, localValue.value)
+    return options.values
   }
 
   return []
 })
+
+// Show the deserialized value as placeholder when it's not in the options list
+// This preserves legacy behavior where workflow values are shown even if deleted
+const selectPlaceholder = computed(() => {
+  const currentValue = localValue.value
+
+  // If there's a current value and it's not in the options, show it as placeholder
+  if (
+    currentValue != null &&
+    currentValue !== '' &&
+    !selectOptions.value.includes(currentValue)
+  ) {
+    return String(currentValue)
+  }
+
+  // Otherwise use the default placeholder from options
+  return props.widget.options?.placeholder
+})
 </script>