Feature request: Support custom icons for skills

Summary

Skills in the Claude Code UI currently all display with the same default document icon, making them visually indistinguishable. It would be great to support a custom icon (emoji or image) per skill.

Motivation

Other tools like Codex already support per-skill icons — for example, showing a 🐻 emoji next to a "Kuma Picker" skill. This small visual cue makes it much easier to scan and identify skills at a glance, especially when you have many skills installed.

!Codex skill icons example

Proposed Solution

Add an optional icon field to the SKILL.md frontmatter:

---
name: kuma-picker
description: Read the latest Kuma Picker selection...
icon: 🐻
---

This could support:

• Emoji — simplest, works everywhere (e.g., icon: 🐻)
• Relative image path — for custom icons (e.g., icon: ./icon.png)

Current Behavior

All skills show the same document icon in the skills list, regardless of the skill's purpose.

Expected Behavior

Each skill can optionally specify an icon that is displayed in the skills list and autocomplete menu.