Claude Code plugins (e.g. frontend-design) should be available in Cowork sessions

Description

Plugins installed in Claude Code (from the anthropics/claude-code marketplace) are not available in Cowork sessions. The two plugin ecosystems are completely disconnected:

• Claude Code uses plugins from anthropics/claude-code (installed via /plugin marketplace add anthropics/claude-code)
• Cowork uses plugins from anthropics/knowledge-work-plugins (installed via the Cowork sidebar)

This means first-party plugins like frontend-design that work in Claude Code CLI are inaccessible when using Cowork, even though both products are made by Anthropic and run on the same underlying system (Claude Agent SDK).

Steps to Reproduce

1. Install frontend-design@claude-code-plugins in Claude Code — works great
2. Open a Cowork session in the Claude desktop app
3. The frontend-design skill is not available — it doesn't appear in the skills list and cannot be invoked
4. Searching the Cowork VM filesystem confirms no frontend-design files exist anywhere

Expected Behavior

Plugins installed in Claude Code should be available in Cowork sessions, or there should be a clear mechanism to sync/share plugins between the two environments.

Current Workaround

Manually downloading the SKILL.md file and placing it in /mnt/.claude/skills/frontend-design/SKILL.md within the Cowork VM. This is fragile (resets between sessions) and shouldn't be necessary for a first-party Anthropic plugin.

Environment

• Claude Desktop App (macOS)
• Cowork mode (research preview)
• Claude Code with frontend-design@claude-code-plugins installed locally