Plugin auto-update orphans all cached versions, leaving no active version at session start

Summary

When autoUpdate: true is configured for a marketplace and a plugin update is downloaded during a session, the auto-update cycle marks the old version as orphaned but also leaves the newly downloaded version in an orphaned state. On the next session start, Claude Code finds no active (non-orphaned) version and does not load the plugin's skills. Running /reload-plugins temporarily restores them.

Steps to Reproduce

1. Configure a marketplace with autoUpdate: true in settings.json
2. Enable a plugin from that marketplace (enabledPlugins)
3. Start a Claude Code session — plugin skills load normally
4. An auto-update runs during the session (new version downloaded, old version orphaned)
5. End the session and start a new one
6. Plugin skills are not available — they do not appear in the skill list

Workaround: run /reload-plugins after each session start to force re-activation.

Expected Behavior

After an auto-update, the newly downloaded version should be activated cleanly so that plugin skills load automatically on the next session start without manual intervention.

Actual Behavior

Both the old and new cached versions have a .orphaned_at marker file:

~/.claude/plugins/cache/ali5ter/claude-workflow-skills/
├── 1.3.3/   (.orphaned_at present — orphaned 2026-05-12)
└── 1.7.1/   (.orphaned_at present — orphaned 2026-05-18, same day as update)

With no active version, the plugin is silently skipped at startup. No error or warning is shown to the user.

Environment

• Claude Code version: 2.1.133
• OS: macOS 15.7.5 (Sequoia, Build 24G624)

Relevant Config (settings.json)

{
  "enabledPlugins": {
    "claude-workflow-skills@ali5ter": true
  },
  "extraKnownMarketplaces": {
    "ali5ter": {
      "source": {
        "source": "github",
        "repo": "ali5ter/claude-plugins"
      },
      "autoUpdate": true
    }
  }
}

Additional Notes

• The plugin (ali5ter/claude-workflow-skills) has no SessionStart hook — skills rely entirely on Claude Code's session-start plugin loading
• The issue appears to affect any plugin under a marketplace with autoUpdate: true, not just this specific plugin
• The /reload-plugins workaround works reliably, suggesting the cached version is valid but the orphaned state prevents it loading at startup

🤖 Generated with Claude Code on behalf of Alister