Local personal skills don't suppress anthropic-skills: duplicates in skill list

Summary

When a user creates skills via the skill-creator and later copies them to ~/.claude/skills/ (the correct personal skills directory), both the local version and the anthropic-skills: version appear in the skills list. The local versions should suppress the duplicates.

Steps to reproduce

1. Create a custom skill via the skill-creator (e.g., barney-voice). This gets stored in ~/Library/Application Support/Claude/local-agent-mode-sessions/skills-plugin/<uuid>/<uuid>/skills/<skill-name>/SKILL.md.
2. Copy the skill to ~/.claude/skills/<skill-name>/SKILL.md (the documented personal skills location).
3. Restart Claude Code.
4. Check the skills list — both barney-voice and anthropic-skills:barney-voice appear.

Expected behavior

The local personal skill (~/.claude/skills/barney-voice/) should take precedence and the anthropic-skills:barney-voice entry should not appear in the skills list.

Actual behavior

Both versions appear in the skills list. Invoking by short name (/barney-voice) does correctly load from ~/.claude/skills/, so the precedence works at invocation time — the issue is cosmetic duplication in the list.

Additional context

• Skills created via skill-creator are stored in a deeply nested path inside ~/Library/Application Support/Claude/local-agent-mode-sessions/skills-plugin/ rather than in ~/.claude/skills/. This means users who want local control of their skills need to manually copy them.
• Deleting the copies from ~/Library/Application Support/... does not persist — Claude Code regenerates them on restart.
• The duplication is confusing for users who aren't sure which version will be invoked.

Environment

• Claude Code version: 2.1.87
• macOS (Darwin 25.3.0)