[BUG] Plugin skills appear duplicated in UI — both plugins/cache/ and plugins/marketplaces/ are scanned

Bug

Plugin skills appear duplicated in the skill listing and UI when both the versioned cache path and the live marketplace path exist for a plugin.

Steps to reproduce

1. Install a plugin from a marketplace
2. Run /reload-plugins
3. Observe that skills like some-plugin:skill (ommited as they are internal) appear twice in the skill listing UI

Root cause

Claude Code scans skills from both:

• ~/.claude/plugins/cache/<marketplace>/<plugin>/<version>/skills/
• ~/.claude/plugins/marketplaces/<marketplace>/plugins/<plugin>/skills/

Both paths contain identical SKILL.md files, so each skill gets registered twice.

Deleting the cache directory (~/.claude/plugins/cache/) is a temporary workaround, but /reload-plugins recreates it immediately, restoring the duplicate.

Expected behavior

Skills should be registered once. Either only the marketplace path or only the cache path should be scanned — not both.

Environment

• OS: macOS