Fix: Vue node/widget positioning and scroll issue (#5441)

* [feat] Refactor overlay compatibility into reusable composable

- Create useTransformCompatOverlayProps composable for centralized overlay prop management
- Update Select, MultiSelect, TreeSelect, and FileUpload components to use composable
- Provides appendTo='self' for transform inheritance in CSS-transformed parents
- Enables easy future additions of other transform compatibility props
- Fix duplicate v-bind attributes by combining props into single computed object

* fix: Keep the canvas container from being scrolled by children

* types: Align the appendTo type with primevue internals

* Update test expectations [skip ci]

---------

Co-authored-by: bymyself <cbyrne@comfy.org>
Co-authored-by: github-actions <github-actions@github.com>

src/composables/useTransformCompatOverlayProps.ts

@@ -0,0 +1,48 @@
+import type { HintedString } from '@primevue/core'
+import { computed } from 'vue'
+
+/**
+ * Options for configuring transform-compatible overlay props
+ */
+interface TransformCompatOverlayOptions {
+  /**
+   * Where to append the overlay. 'self' keeps overlay within component
+   * for proper transform inheritance, 'body' teleports to document body
+   */
+  appendTo?: HintedString<'body' | 'self'> | undefined | HTMLElement
+  // Future: other props needed for transform compatibility
+  // scrollTarget?: string | HTMLElement
+  // autoZIndex?: boolean
+}
+
+/**
+ * Composable that provides props to make PrimeVue overlay components
+ * compatible with CSS-transformed parent elements.
+ *
+ * Vue nodes use CSS transforms for positioning/scaling. PrimeVue overlay
+ * components (Select, MultiSelect, TreeSelect, etc.) teleport to document
+ * body by default, breaking transform inheritance. This composable provides
+ * the necessary props to keep overlays within their component elements.
+ *
+ * @param overrides - Optional overrides for specific use cases
+ * @returns Computed props object to spread on PrimeVue overlay components
+ *
+ * @example
+ * ```vue
+ * <template>
+ *   <Select v-bind="overlayProps" />
+ * </template>
+ *
+ * <script setup>
+ * const overlayProps = useTransformCompatOverlayProps()
+ * </script>
+ * ```
+ */
+export function useTransformCompatOverlayProps(
+  overrides: TransformCompatOverlayOptions = {}
+) {
+  return computed(() => ({
+    appendTo: 'self' as const,
+    ...overrides
+  }))
+}