Feature request: allow disabling built-in skills

Problem

There is currently no way to disable, hide, or uninstall built-in skills (e.g., claude-developer-platform). These skills can auto-trigger unintentionally, and users have no mechanism to prevent this.

What I've investigated

• Built-in skills have no physical files in ~/.claude/skills/, ~/.claude/commands/, or plugin directories
• settings.json enabledPlugins only applies to marketplace plugins
• plugins/blocklist.json also only applies to marketplace plugins
• /plugin disable only targets installed (non-built-in) plugins

Use cases

1. Prevent unintended auto-triggering: Built-in skills may activate when not needed, consuming tokens and producing unwanted output
2. Simplify skill list: Users who don't need certain built-in skills should be able to hide them from the active skill set
3. Avoid conflicts: Built-in skills may conflict with user-defined skills or commands that serve a similar purpose

Proposed solutions (any of these would work)

1. disabledSkills in settings.json: Add a new array field where users can list built-in skill names to disable

``json
{
"disabledSkills": ["claude-developer-platform"]
}
``

1. Extend /plugin disable to built-in skills: Allow the existing /plugin disable <name> command to also target built-in skills

1. Per-skill toggle in /plugin UI: Show built-in skills in the plugin management interface with an enable/disable toggle

Environment

• Claude Code CLI (latest)
• OS: Linux (WSL2)