task (release): Add workflow to publish binaries for each platform.

.github/workflows/release.yml

@@ -0,0 +1,142 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Tag to release (e.g., v0.11.0). Leave empty to use latest tag.'
+        required: false
+        type: string
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    name: Build ${{ matrix.os }}-${{ matrix.arch }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - os: linux
+            arch: amd64
+            extension: ''
+          - os: linux
+            arch: arm64
+            extension: ''
+          - os: darwin
+            arch: amd64
+            extension: ''
+          - os: darwin
+            arch: arm64
+            extension: ''
+          - os: windows
+            arch: amd64
+            extension: '.exe'
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - name: Determine version
+        id: version
+        run: |
+          if [ "${{ github.event_name }}" = "workflow_dispatch" ] && [ -n "${{ inputs.tag }}" ]; then
+            TAG="${{ inputs.tag }}"
+          elif [ "${{ github.event_name }}" = "push" ]; then
+            TAG="${GITHUB_REF#refs/tags/}"
+          else
+            TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "v0.0.0")
+          fi
+          VERSION="${TAG#v}"
+          echo "tag=${TAG}" >> $GITHUB_OUTPUT
+          echo "version=${VERSION}" >> $GITHUB_OUTPUT
+
+      - name: Set up Go
+        uses: actions/setup-go@v6
+        with:
+          go-version: '1.25'
+
+      - name: Build binary
+        env:
+          GOOS: ${{ matrix.os }}
+          GOARCH: ${{ matrix.arch }}
+          CGO_ENABLED: 0
+        run: |
+          VERSION="${{ steps.version.outputs.version }}"
+          OUTPUT_NAME="gmailctl${{ matrix.extension }}"
+          go build -ldflags="-s -w -X github.com/mbrt/gmailctl/cmd/gmailctl/cmd.version=${VERSION}" \
+            -o "${OUTPUT_NAME}" ./cmd/gmailctl
+
+      - name: Create archive (Unix)
+        if: matrix.os != 'windows'
+        run: |
+          VERSION="${{ steps.version.outputs.version }}"
+          ARCHIVE_NAME="gmailctl_${VERSION}_${{ matrix.os }}_${{ matrix.arch }}.tar.gz"
+          tar -czvf "${ARCHIVE_NAME}" gmailctl
+          echo "ARCHIVE_NAME=${ARCHIVE_NAME}" >> $GITHUB_ENV
+
+      - name: Create archive (Windows)
+        if: matrix.os == 'windows'
+        run: |
+          VERSION="${{ steps.version.outputs.version }}"
+          ARCHIVE_NAME="gmailctl_${VERSION}_${{ matrix.os }}_${{ matrix.arch }}.zip"
+          zip "${ARCHIVE_NAME}" gmailctl.exe
+          echo "ARCHIVE_NAME=${ARCHIVE_NAME}" >> $GITHUB_ENV
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: gmailctl-${{ matrix.os }}-${{ matrix.arch }}
+          path: ${{ env.ARCHIVE_NAME }}
+          retention-days: 1
+
+  release:
+    name: Create Release
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - name: Determine version
+        id: version
+        run: |
+          if [ "${{ github.event_name }}" = "workflow_dispatch" ] && [ -n "${{ inputs.tag }}" ]; then
+            TAG="${{ inputs.tag }}"
+          elif [ "${{ github.event_name }}" = "push" ]; then
+            TAG="${GITHUB_REF#refs/tags/}"
+          else
+            TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "v0.0.0")
+          fi
+          echo "tag=${TAG}" >> $GITHUB_OUTPUT
+
+      - name: Download all artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: dist
+          merge-multiple: true
+
+      - name: Generate checksums
+        run: |
+          cd dist
+          sha256sum gmailctl_* > checksums.txt
+
+      - name: Create Release
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: ${{ steps.version.outputs.tag }}
+          name: Release ${{ steps.version.outputs.tag }}
+          draft: false
+          prerelease: ${{ contains(steps.version.outputs.tag, '-') }}
+          generate_release_notes: true
+          files: |
+            dist/gmailctl_*
+            dist/checksums.txt