Skill portability between Claude Code and Claude.ai

Feature Request

Problem: Skills created in Claude Code (~/.claude/skills/) are invisible to the Claude.ai web/desktop app, and vice versa. There's no shared skill registry between the two surfaces.

Current behavior:

• Claude Code skills are local markdown files with frontmatter, invoked via /skill-name in the CLI
• Claude.ai has Custom Instructions and Project Knowledge, but no concept of slash-command skills
• The two systems are completely disconnected

Desired behavior:

• Skills defined in Claude Code should be discoverable and invocable in Claude.ai (and vice versa)
• A shared skill registry (perhaps synced via Claude account) would allow users to build skills once and use them everywhere
• Slash-command invocation (/skill-name) should work consistently across both surfaces

Why this matters:

• Power users invest significant time building skill libraries (I have 70+ skills across projects)
• Context switching between Claude Code and Claude.ai means losing access to those skills
• Skills encode domain knowledge and workflows that are valuable regardless of which interface you're using

Suggested approach:

• Sync ~/.claude/skills/ to the user's Claude account
• Render them as invocable slash commands in Claude.ai's chat interface
• Support the same frontmatter format (name, description, allowed-tools, argument-hint)