## Summary
Extract internal logic from the 2 remaining VTU holdout components into
composables, enabling full VTL migration.
## Changes
- **What**: Extract `useProcessedWidgets` from `NodeWidgets.vue`
(486→135 LOC) and `useWidgetSelectItems`/`useWidgetSelectActions` from
`WidgetSelectDropdown.vue` (563→170 LOC). Rewrite both component test
files as composable unit tests + slim behavioral VTL tests. Remove
`@vue/test-utils` devDependency.
- **Dependencies**: Removes `@vue/test-utils`
## Review Focus
- Composable extraction is mechanical — no logic changes, just moving
code into testable units
- `useProcessedWidgets` handles widget deduplication, promotion border
styling, error detection, and identity resolution (~290 LOC)
- `useWidgetSelectItems` handles the full computed chain from widget
values → dropdown items including cloud asset mode and multi-output job
resolution (~350 LOC)
- `useWidgetSelectActions` handles selection resolution and file upload
(~120 LOC)
- 40 new composable-level unit tests replace 13 `wrapper.vm.*` accesses
across the 2 holdout files
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10966-refactor-extract-composables-from-VTU-holdout-components-complete-VTL-migration-33c6d73d36508148a3a4ccf346722d6d)
by [Unito](https://www.unito.io)
---------
Co-authored-by: Amp <amp@ampcode.com>
