Add skillet skill-routed PR reviewer workflow

[Copilot]

This adds a new PR review workflow, skillet, that treats slash commands as skill selectors under .github/skills. It pre-filters unmatched commands before agent execution, then runs a Copilot-based review with PR-safe outputs.

• New workflow: skillet

  • Adds .github/workflows/skillet.md as a centralized slash-command reviewer with the 🍳 identity.
  • Triggers on PR comment and PR review comment slash commands.
  • Interprets the command name as a repository skill name and passes the remaining comment text through as the review request.

• Pre-activation skill gating

  • Adds a pre-activation matcher that:
    • checks PR context,
    • resolves /.github/skills/<command>/SKILL.md,
    • checks centralized command routing metadata from the generated command router workflow,
    • exposes the matched skill path and trailing request text,
    • cancels before agent execution when no skill matches.
  • When neither a repository skill nor a centralized command route matches, pre-activation posts a pull request comment listing the available commands.
  • This keeps non-skill commands out of the expensive review path while giving contributors an in-band command discovery fallback.

• PR review execution model

  • Runs Copilot with copilot-requests: write.
  • Reuses the standard PR review safe-output pattern:
    • inline review comments,
    • final review submission,
    • optional check-run on approval,
    • explicit noop when nothing actionable is found.

• Catch-all slash-command support

  • Extends slash-command validation/runtime support to allow bare * as a catch-all centralized route.
  • Keeps prefix wildcard behavior (for example smoke*) intact while making * an explicit non-empty catch-all.

• Routing coverage

  • Adds test coverage for catch-all slash routing so the dispatched workflow receives the actual matched command name.

Example of the new routing shape:

on:
  slash_command:
    strategy: centralized
    name: "*"
    events: [pull_request_comment, pull_request_review_comment]

A comment like:

/developer review auth changes

now resolves to .github/skills/developer/SKILL.md, and review auth changes becomes the reviewer’s task-specific request.

[pelikhan]

@copilot use actions/github-script instead of python

[Copilot]

Fixed in fb2b987.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[pelikhan]

@copilot when skillet can't find a matching slash command (and also there isn't any matching commands in the agentic-maintenance.yml file), it should post a comment with the available commands. Must be done in pre-activation.

[github-actions]

@copilot please reply with the available slash commands before activation.

Generated by 👨‍🍳 PR Sous Chef · 38.5 AIC · ⌖ 1.02 AIC · ⊞ 17.2K · ◷

[Copilot]

@copilot when skillet can't find a matching slash command (and also there isn't any matching commands in the agentic-maintenance.yml file), it should post a comment with the available commands. Must b...

Fixed in 9c6f77e.

[github-actions]

@copilot review all comments and address unresolved review feedback.

Generated by 👨‍🍳 PR Sous Chef · 40.4 AIC · ⌖ 1 AIC · ⊞ 17.2K · ◷

[github-actions]

@copilot please refresh the branch and summarize any remaining blockers.

Generated by 👨‍🍳 PR Sous Chef · 40.4 AIC · ⌖ 1 AIC · ⊞ 17.2K · ◷