Marketplace update button is disabled/not pressable even when version is outdated

Description

The Update button in the plugin marketplace UI is unresponsive even when an update is available. The button appears in the customize menu but cannot be clicked — it is greyed out and non-interactive regardless of the version state.

Steps to Reproduce

1. Add a git-based marketplace (e.g. https://github.com/DojoGenesis/plugins.git)
2. Push new commits to the remote repository so a newer version is available
3. Open Claude Code → plugin customize menu → find the marketplace
4. Observe that the version shown is outdated but the Update button is disabled/not pressable

Expected Behavior

The Update button is clickable and triggers a fresh git pull to bring the local clone up to date with the remote.

Actual Behavior

The Update button is present but disabled — it cannot be pressed regardless of version state, even when the local clone is behind the remote.

Additional Context

This is one of several related marketplace lifecycle bugs that suggest the marketplace state manager has broad lifecycle issues around create/update/delete operations:

• The marketplace cannot be deleted from the customize menu (issue #45649)
• Marketplace git clones are created empty (issue #45653)
• This issue: the Update button is always disabled

All three point to the same underlying area of the marketplace lifecycle management code.