ci: release per-target archives with one checksum file and provenance

.github/workflows/release.yml

@@ -0,0 +1,144 @@
+name: Release
+
+# Runs on a pushed v* tag and creates a DRAFT pre-release. A maintainer
+# reviews the attached archives, SHA256SUMS and provenance attestation before
+# publishing it. Only targets that CI tests are built; Windows is compile-only
+# in CI and is not released.
+
+on:
+  push:
+    tags: ['v*']
+
+permissions:
+  contents: read
+
+concurrency:
+  group: release-${{ github.ref }}
+  cancel-in-progress: false
+
+env:
+  GO_VERSION: "1.26.6"
+  GOTOOLCHAIN: local
+  GOWORK: "off"
+
+jobs:
+  build:
+    strategy:
+      fail-fast: true
+      matrix:
+        include:
+          - os: ubuntu-latest
+            goos: linux
+            goarch: amd64
+          - os: macos-latest
+            goos: darwin
+            goarch: arm64
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+      - uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
+        with:
+          go-version: ${{ env.GO_VERSION }}
+          cache: false
+      - name: Tag matches source version
+        shell: bash
+        run: |
+          set -euo pipefail
+          source_version="$(tr -d '\r\n' < VERSION)"
+          binary_version="$(go run ./cmd/across version)"
+          if [ "v${source_version}" != "${GITHUB_REF_NAME}" ] || [ "${binary_version}" != "${source_version}" ]; then
+            echo "::error::tag ${GITHUB_REF_NAME}, VERSION ${source_version} and 'across version' ${binary_version} must agree"
+            exit 1
+          fi
+      - name: Runner matches target
+        shell: bash
+        run: |
+          set -euo pipefail
+          actual="$(go env GOOS)/$(go env GOARCH)"
+          if [ "${actual}" != "${{ matrix.goos }}/${{ matrix.goarch }}" ]; then
+            echo "::error::runner builds ${actual}, expected ${{ matrix.goos }}/${{ matrix.goarch }}"
+            exit 1
+          fi
+      - name: Test
+        run: go test -count=1 ./...
+      - name: Build and package
+        shell: bash
+        env:
+          CGO_ENABLED: "1"
+          COPYFILE_DISABLE: "1"
+        run: |
+          set -euo pipefail
+          name="across_${GITHUB_REF_NAME#v}_${{ matrix.goos }}_${{ matrix.goarch }}"
+          stage="dist/${name}"
+          mkdir -p "${stage}"
+          go build -trimpath -o "${stage}/across" ./cmd/across
+          for agent in claude-code codex cursor gemini opencode qwen factory-droid amp goose; do
+            go build -trimpath -o "${stage}/across-agent-${agent}" "./cmd/across-agent-${agent}"
+          done
+          cp LICENSE README.md CHANGELOG.md "${stage}/"
+          tar -C dist -czf "dist/${name}.tar.gz" "${name}"
+          rm -rf "${stage}"
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: across-${{ matrix.goos }}-${{ matrix.goarch }}
+          path: dist/*.tar.gz
+          if-no-files-found: error
+
+  publish:
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      id-token: write
+      attestations: write
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+      - uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
+        with:
+          go-version: ${{ env.GO_VERSION }}
+          cache: false
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          path: dist
+          pattern: across-*
+          merge-multiple: true
+      - name: Module inventory
+        run: go list -m -json all > dist/go-modules.json
+      - uses: anchore/sbom-action@3ad7283483fc7af8ff2b4ea19663c2d5ca935e26 # v0.24.2
+        with:
+          path: .
+          format: spdx-json
+          output-file: dist/sbom.spdx.json
+          syft-version: v1.51.1
+          upload-artifact: false
+          upload-release-assets: false
+      - name: Checksums
+        shell: bash
+        run: |
+          set -euo pipefail
+          cd dist
+          archives=(across_*.tar.gz)
+          if [ "${#archives[@]}" -ne 2 ]; then
+            echo "::error::expected 2 archives, found ${#archives[@]}: ${archives[*]}"
+            exit 1
+          fi
+          sha256sum across_*.tar.gz go-modules.json sbom.spdx.json > SHA256SUMS
+          cat SHA256SUMS
+      - uses: actions/attest-build-provenance@4d101475d8b20a2381f78447822ac1eab6504dd8 # v4.2.2
+        with:
+          subject-checksums: dist/SHA256SUMS
+      - uses: softprops/action-gh-release@da05d552573ad5aba039eaac05058a918a7bf631 # v2.2.2
+        with:
+          draft: true
+          prerelease: true
+          generate_release_notes: true
+          fail_on_unmatched_files: true
+          files: |
+            dist/across_*.tar.gz
+            dist/SHA256SUMS
+            dist/go-modules.json
+            dist/sbom.spdx.json