[FEATURE] Slash command autocomplete should search against group/namespace tags

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

Skills from packages like superpowers are displayed in autocomplete with a group tag — e.g., /requesting-code-review (superpowers). However, the autocomplete search only matches against the display name, not the group tag.

This means typing /superpowers does not surface any of the ~15 active superpowers skills (requesting-code-review, systematic-debugging, test-driven-development, etc.). It only matches the 3 deprecated stubs that happen to have "superpowers" literally in their display name.

This makes it impossible to discover all skills in a package by typing the package name, which is the most natural way to browse them.

Proposed Solution

Typing /superpowers should match against the group tag (superpowers) and show all skills in that namespace. The autocomplete search index should include both the display name and the group/namespace tag.

Alternative Solutions

Currently the only workaround is to remember the individual skill names and type them directly (e.g., /requesting, /systematic, /verification), which defeats the purpose of namespace grouping for discoverability.

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

1. I install the superpowers skill package which adds ~15 skills
2. I can't remember all the skill names
3. I type /superpowers expecting to see all skills from that package
4. Only 3 deprecated stubs appear — the active skills are hidden
5. With this fix, all 15 skills would appear, making the namespace useful for discovery

Additional Context

Current behavior:

• /superpowers → shows only 3 deprecated stubs (display names: superpowers:write-plan, superpowers:brainstorm, superpowers:execute-plan)
• /requesting → shows requesting-code-review with (superpowers) tag — but this skill is not discoverable by typing /superpowers

Claude Code v2.1.81 on macOS.