Allow users to configure or pin skill launcher priority

What feature would you like to see?

Please allow users to configure or pin the ordering priority of Skills and Plugins in the $ mention launcher.

This request is related to, but distinct from, #31247.

Issue #31247 asks for exact invocation matches to rank above prefix and fuzzy matches. This request asks for an additional user-controlled tie-breaker among otherwise comparable launcher results.

Motivation

For example, typing $repo currently shows results such as:

Design Report          [Skill]
GitHub Repo Workflow   [Skill]
Setup Repo             [Skill]
landing-report         [Skill]

Setup Repo is a user-authored Skill whose canonical invocation is $repo, but users currently have no way to pin or prioritize it in the launcher.

Even after exact-match ranking is fixed, configurable priority would still be useful when:

• multiple Skills have similar names or purposes;
• local Skills overlap with bundled or Plugin-provided Skills;
• users want frequently used Skills near the top;
• two Skills share the same canonical name from different discovery scopes.

Suggested behavior

Preserve relevance as the primary ordering rule:

1. Exact invocation / insert_text
2. Exact display name
3. Prefix match
4. Fuzzy match

Within the same relevance tier, apply:

1. User-configured priority or pinned state
2. Existing Plugin/Skill type rank and default ordering

User priority should not allow an unrelated fuzzy match to outrank an exact invocation.

Possible configuration

One option would be to extend the existing path-based Skill configuration:

[[skills.config]]
path = "/absolute/path/to/repo/SKILL.md"
enabled = true
launcher_priority = 100

Using the Skill path rather than only its name would avoid ambiguity when multiple discovery scopes contain Skills with the same name.

A simpler UI alternative would be a “Pin to top” action in the Skill launcher or Skills settings.

Expected behavior

• Users can pin or prioritize a specific Skill or Plugin launcher entry.
• Configuration identifies the exact Skill even when names collide.
• Exact invocation matches still outrank prefix and fuzzy matches.
• Priority is applied consistently in the CLI, IDE extension, and Codex app wherever the $ launcher is available.
• Removing the configuration restores the default ordering.
• Existing configurations remain backward compatible.

Related issues

• #31247 — Exact skill names should rank above fuzzy matches
• #21425 — Separate installed plugins from per-session skill metadata injection