User-defined plugin skills not appearing in available_skills

Description

User-defined plugin skills are not appearing in the available_skills list that Claude receives in the system prompt, while official plugins (anthropic-agent-skills, claude-plugins-official) work correctly.

Steps to Reproduce

1. Install a user-defined plugin from a custom marketplace (e.g., zzoony-claude-config)
2. The plugin contains skills with proper SKILL.md files including frontmatter (name, description)
3. Skills are shown as installed and enabled in /plugin list
4. However, skills do not appear in Claude's available_skills section

Expected Behavior

User-defined plugin skills should appear in available_skills so Claude can automatically recognize and invoke them based on trigger keywords.

Actual Behavior

• Official plugins (document-skills:pdf, document-skills:docx, etc.) appear in available_skills
• User-defined plugins (daily-log-skill, etc.) do NOT appear in available_skills
• Claude cannot automatically recognize the skill and must manually search for the SKILL.md file

Environment

• Plugin list shows skills as installed and enabled (green dot)
• SKILL.md has proper frontmatter format:

---
name: daily-log
description: 프로젝트의 daily log를 작성합니다...
---

Plugin Structure Comparison

Official (works):

anthropic-agent-skills/document-skills/
└── skills/
    ├── pdf/SKILL.md
    └── docx/SKILL.md

User-defined (not working):

zzoony-claude-config/daily-log-skill/
└── 1.0.0/
    └── SKILL.md

Workaround

Currently, the user must explicitly tell Claude to search for the skill file, or Claude must manually read the SKILL.md file path.

Suggestion

Please ensure user-defined plugin skills are included in the available_skills list passed to Claude in the system prompt.