Add Makefile for local builds and GitHub Releases to workflow

[tig]

Summary

AOT publish is configured and works in CI, but there's no local convenience for building native binaries. The release workflow builds artifacts but doesn't create GitHub Releases with downloadable binaries.

What to do

1. Create Makefile at repo root

Convenience Makefile for local builds and AOT publishing. Auto-detects RID from uname.

Target	What it does
make restore	dotnet restore
make build	Debug build (depends on restore)
make build-release	Release build
make test	Runs all three test projects (unit, integration, smoke)
make publish	AOT publish for current platform to publish/<rid>/. Accepts RID=linux-x64 override
make publish-all	AOT publish for osx-arm64, linux-x64, win-x64
make clean	rm -rf publish/ + dotnet clean

Publish command: dotnet publish src/Clet -c Release -r $(RID) --self-contained -p:PublishAot=true -o publish/$(RID)

2. Add release job to .github/workflows/release.yml

Insert a new job after tag and before publish-nuget. Also add release to the notify-failure job's needs array.

• needs: [resolve-version, build, tag]
• runs-on: ubuntu-latest
• Steps:
  1. Download all artifacts via actions/download-artifact@v4 to artifacts/
  2. Create archives in dist/:
     • macOS/Linux: tar -czf dist/clet-<version>-<rid>.tar.gz (after chmod +x clet)
     • Windows: zip -r dist/clet-<version>-win-x64.zip
     • Skip missing artifacts with a warning
  3. Create GitHub Release via gh release create v<version>:
     • --title "clet v<version>"
     • --generate-notes
     • --prerelease if version contains - (alpha, develop)
     • Attach all files from dist/*
     • Uses GITHUB_TOKEN and github.repository env vars

3. Update CLAUDE.md Build and Test section

• Add dotnet run --project tests/Clet.SmokeTests --no-build to the test commands
• Add a section documenting the Makefile targets

Verification

make publish
./publish/osx-arm64/clet --version
./publish/osx-arm64/clet list
./publish/osx-arm64/clet help --cat

Notes

• A local commit implementing this exists on feature/makefile-releases (38ea5db) but couldn't be pushed due to SSH agent being unavailable remotely. The branch can be pushed manually or the work can be redone from this spec.
• Don't modify existing workflow jobs (build, tag, publish-nuget, etc.) — only add the new release job and update notify-failure's needs array.