Per-marketplace autoUpdate toggle is missing from Claude Code Desktop UI

Summary

The "Enable auto-update" option for a marketplace is only accessible from Claude Code CLI (/plugins → Marketplaces → <name> → Enable auto-update). Claude Code Desktop's Customize panel does not surface this toggle anywhere. Desktop-only users cannot enable per-marketplace auto-update through any GUI path.

Reproduction

1. Use Claude Code Desktop with no terminal access.
2. Add a marketplace via Customize → Add plugin.
3. Search Desktop's UI for an "auto-update" toggle for that marketplace.

Expected

A per-marketplace auto-update toggle is surfaced somewhere accessible from the GUI.

Actual

No such toggle exists. The flag (autoUpdate: true) only writes to ~/.claude/settings.json and ~/.claude/plugins/known_marketplaces.json when toggled from the CLI menu.

Environment

Claude Code Desktop v2.1.121, macOS.

Impact

A documented platform feature is gated behind terminal access. Non-technical users on Desktop cannot enable it.