Remove deprecated `vintageClipboard` — 3 consumers remain

## Recommendation

### 🔀 CONSOLIDATE: Complete Migration Away from vintageClipboard

`vintageClipboard` is marked as deprecated but is still imported by 3 files. The modern clipboard system exists and should be used instead.

## What Was Found

- `vintageClipboard` is explicitly deprecated
- 3 files still import it
- Modern clipboard implementation is available

## How to Fix

1. Migrate the 3 remaining consumers to the modern clipboard API
2. Remove `vintageClipboard`

---
**Category:** Vestigial Systems | **Priority:** Recommended | **Effort:** Small
Part of #11022
_Filed by repo-audit skill_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-11067-Remove-deprecated-vintageClipboard-3-consumers-remain-33e6d73d3650814fbb4fc2d63bf5f913) by [Unito](https://www.unito.io)