feat(copilot): add VS Code Copilot skill compatibility and docs

[hatimbenayad]

• mirror skill packs from .claude/skills to .github/skills for Copilot discovery

• normalize copied skill metadata and path references for .github layout

• add workspace-level Copilot instructions at .github/copilot-instructions.md

• document manual GitHub Copilot setup in README

[mrgoonie]

Cron-safe maintainer pass: deferring this PR from the bounded review lane because it is too large for a safe metadata-first run (189 files, +22,246/-0) and GitHub cannot even serve the full diff through the normal diff API.

Please narrow this into focused PRs before maintainer review:

• one PR for the workspace-level Copilot instructions/docs, and
• separate generated/mirrored skill-pack PRs only if there is a documented, repeatable source-of-truth sync command.

Acceptance bar for a future review: explain why .github/skills should duplicate the full .claude/skills tree instead of being generated during release/install, include the sync command, and prove the duplicated skill metadata/path rewrites stay in sync with canonical skill sources.

[clark-cant]

Stale content — needs rebase to sync with recent path-portability fixes

This PR mirrors skills to .github/skills/ for Copilot compatibility, which is valuable. However, the branch was created on April 15 and hasn't been updated since June 24. In the intervening months, the repository has undergone significant path-portability work:

• PR fix(design): skill-relative script paths + CI path contract (#474 finding 1) #476 (merged 2026-09-03): Fixed hard-coded ~/.claude/skills/design/scripts/... invocations in design/SKILL.md — replaced with skill-relative paths
• PR fix(data): make catalog snapshot hashes line-ending independent #478 (merged 2026-09-03): Fixed shipped-data line-ending integrity for catalog-summary.json verification
• PR fix(skills): finish the skill-relative path contract below SKILL.md (#474 finding 1) #482 (merged 2026-09-03): Extended path fixes to all references/ files and code paths (92+ invocations across multiple skills), added comprehensive path-contract tests

The mirrored copies in .github/skills/ in this PR almost certainly contain the old hard-coded paths that were just fixed in the canonical .claude/skills/ copies. Merging as-is would reintroduce the exact portability defects that PRs #476/#482 resolved.

Required before merge:

1. Rebase onto current main to pick up the path-portability fixes
2. Ensure the mirrored .github/skills/ copies reflect the skill-relative path convention now used in .claude/skills/
3. Verify the path-contract tests in check-asset-sync.yml also cover the .github/skills/ tree, or add equivalent coverage

The strategic value is clear — Copilot support is a legitimate platform target. But the mirror needs to stay in sync with the source of truth, especially after infrastructure fixes like these.

Status: Requesting rebase/update. Will re-review once the branch reflects current main.

Posted by github-maintain cron

[clark-cant]

Review: feat(copilot): add VS Code Copilot skill compatibility and docs

Summary: This PR mirrors the entire .claude/skills/ tree into .github/skills/ for GitHub Copilot skill discovery, adds workspace-level Copilot instructions, and updates the README.

Risk level: Medium — large surface area (189 files, +22,246 lines), but additive-only (0 deletions) and structurally mechanical.

Mandatory Gates

• Duplicate / prior implementation: Partial overlap. PR #17 (merged) added Copilot CLI support via .github/prompts/. PR #328 (merged) added .prompt.md generation. This PR takes a different approach — placing skills directly in .github/skills/ for native Copilot discovery. Issue #454 explicitly requests this direction ("Skills instead of Prompts"). Not a duplicate, but the relationship between the two approaches (prompts vs. skills) should be documented.

• Project standards: No formal standards doc found. Reviewing against observed patterns: the repo maintains skills under .claude/skills/ with a consistent structure. This PR preserves that structure in the new location.

• Strategic necessity: Clear value — Issue #454 has been open since Aug 2023 requesting Copilot skill support. This PR delivers it.

Findings

Important:

1. Maintenance burden — 22K lines of mirrored content. Every future change to a skill file must now be made in two places. There is no sync script, no CI check, and no documentation about this requirement. This will drift.

   Suggested fix (pick one):

   • Add a scripts/sync-skills-to-github.sh that copies .claude/skills/ → .github/skills/ and wire it into the release workflow
   • Or: add a CI check that diffs the two trees and fails if they diverge
   • Or: at minimum, add a CONTRIBUTING.md note explaining the dual-location requirement

2. No link to Issue #454. Please add Closes #454 (or Partial fix for #454) to the PR body so the issue is tracked.

Suggestion:

3. The .github/copilot-instructions.md file is good but brief. Consider linking to the Copilot skills documentation for discoverability.

Verdict: Request Changes

The approach is sound and addresses a real need, but the 22K-line mirror without a sync mechanism creates a maintenance trap. One of the three fixes above (sync script, CI check, or documented manual process) is needed before merge.

Posted by github-maintain automation at $(date -u +'%Y-%m-%dT%H:%M:%SZ')