[FEATURE] Show user-level skills in VS Code extension's / command menu

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When I type / in the VS Code extension's chat input, the command menu shows built-in commands and plugin-provided skills — but not my custom skills from ~/.claude/skills/. I'd like user-level skills to appear in this menu so they're discoverable without memorizing names.

I maintain reusable skills in ~/.claude/skills/ (debugging workflows, QA testing, security audits, design review) that I use across multiple projects. Today I have to remember and type the exact slash command name each time. If I share these skills with teammates, they have no way to discover what's available without browsing the filesystem.

Proposed Solution

The / command menu in the VS Code extension enumerates ~/.claude/skills/*/SKILL.md alongside existing sources. Each skill already has name and description frontmatter that could populate the menu label and hint text.

Alternative Solutions

I have to remember or look up and then type the exact slash command name each time.

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

Example:

1. I just added Garry Tan's gstack skills in an external repo and set them up to work through ~/.claude/skills/
2. I want to use /design-review, which are set up to be called with /gstack-design-review.
3. Because I don't yet have the exact command memorized, I need to look at a reference and then type or paste in the command to invoke the skill.

I have become used to the convenience of typing a / and then seeing the list of options appear. Needing to use a reference until I have them memorized is a bit of friction I would like to have removed.

Additional Context

_No response_