Cowork (desktop) can't update a custom git-marketplace plugin — reverts to old version on relaunch; blocks scheduled tasks

Summary

A custom plugin distributed via a git-based marketplace updates correctly in Claude Code (CLI) but cannot be updated in Claude Cowork (desktop). Cowork stays pinned to an old version, reverts manual .plugin uploads on relaunch, and offers no supported path to push a newer version. This blocks scheduled/unattended Cowork tasks that depend on the updated skills.

Environment

• macOS · Claude desktop / Cowork (updater ~1.10628.2) · bundled claude-code 2.1.161
• Custom plugin megamind-coach from a personal git marketplace (github.com/jamesbrackmusic-cell/megamind-athletics, with .claude-plugin/marketplace.json)

Repro

1. Install a custom plugin (v1.1.0) from the git marketplace — works in Cowork.
2. Update the plugin in the repo to v1.3.1 (new commands/skills) and push to the default branch (main).
3. Claude Code (CLI): /plugin marketplace update → loads v1.3.1 correctly. ✅
4. Cowork (desktop): still shows v1.1.0. /plugin marketplace update, uninstall+reinstall, and a full app quit+relaunch+new conversation all leave it at v1.1.0. ❌
5. Manually uploading a freshly-packaged v1.3.1 .plugin works for that session only — it reverts to v1.1.0 on the next relaunch.

Likely cause (from local inspection)

• Cowork appears to run claude-code inside a VM (~/Library/Application Support/Claude/vm_bundles/claudevm.bundle) and provision plugins per-session from a managed account/remote source. It does not read ~/.claude/plugins, where the CLI's marketplace cache is correctly at v1.3.1.
• ~/Library/Application Support/Claude/config.json contains "remote_marketplace_migration_done_v1": true.
• Net: the host-side git marketplace and manual uploads don't persist into Cowork; the managed source stays at the last-published version.

Impact

• No supported way for a user to update a personal/custom plugin in Cowork.
• Scheduled Cowork tasks that depend on newer skills run against the stale version — e.g., a weekly task that invokes a skill added in v1.2.0 fails because that skill isn't present in the v1.1.0 copy Cowork provisions.

Request

A supported mechanism to either (a) update/persist a personal custom plugin in Cowork, or (b) have Cowork honor the local/git marketplace (and/or manual .plugin uploads) across relaunches.