feat: add release workflow with automated binary builds

Add automated release process that builds binaries for multiple
platforms and creates GitHub releases with downloadable artifacts.

Changes:
- Add release workflow triggered by vX.Y.Z tags
- Build matrix for Linux (amd64, arm64), macOS (amd64, arm64), Windows (amd64)
- Generate SHA256 checksums for all binaries
- Create GitHub release with auto-generated notes
- Add version command to CLI (wt version)
- Inject version via ldflags during build
- Use GitHub App authentication for release creation

To create a release:
  git tag v1.0.0
  git push origin v1.0.0

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: timvw

.github/workflows/release.yml

@@ -0,0 +1,104 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v[0-9]+.[0-9]+.[0-9]+'
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    name: Build Binaries
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - goos: linux
+            goarch: amd64
+            output: wt-linux-amd64
+          - goos: linux
+            goarch: arm64
+            output: wt-linux-arm64
+          - goos: darwin
+            goarch: amd64
+            output: wt-darwin-amd64
+          - goos: darwin
+            goarch: arm64
+            output: wt-darwin-arm64
+          - goos: windows
+            goarch: amd64
+            output: wt-windows-amd64.exe
+
+    steps:
+      - name: Generate GitHub App token
+        id: generate-token
+        uses: actions/create-github-app-token@v1
+        with:
+          app-id: ${{ secrets.BOT_APP_ID }}
+          private-key: ${{ secrets.BOT_PRIVATE_KEY }}
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          token: ${{ steps.generate-token.outputs.token }}
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.23'
+
+      - name: Build binary
+        env:
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+        run: |
+          mkdir -p dist
+          go build -ldflags="-s -w -X main.version=${{ github.ref_name }}" -o dist/${{ matrix.output }} .
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.output }}
+          path: dist/${{ matrix.output }}
+          if-no-files-found: error
+
+  release:
+    name: Create Release
+    needs: build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Generate GitHub App token
+        id: generate-token
+        uses: actions/create-github-app-token@v1
+        with:
+          app-id: ${{ secrets.BOT_APP_ID }}
+          private-key: ${{ secrets.BOT_PRIVATE_KEY }}
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          token: ${{ steps.generate-token.outputs.token }}
+
+      - name: Download all artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: dist/
+          merge-multiple: true
+
+      - name: Generate checksums
+        run: |
+          cd dist
+          shasum -a 256 * > checksums.txt
+          cat checksums.txt
+
+      - name: Create GitHub Release
+        env:
+          GH_TOKEN: ${{ steps.generate-token.outputs.token }}
+        run: |
+          gh release create ${{ github.ref_name }} \
+            --title "Release ${{ github.ref_name }}" \
+            --generate-notes \
+            dist/*

README.md

@@ -79,6 +79,9 @@ wt prune
 # Show shell integration code
 wt shellenv
 
+# Show version
+wt version
+
 # Show help
 wt --help
 wt <command> --help

main.go

@@ -11,7 +11,10 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var worktreeRoot string
+var (
+	version      = "dev"
+	worktreeRoot string
+)
 
 func init() {
 	// Set worktree root from environment or default
@@ -48,6 +51,7 @@ func init() {
 	rootCmd.AddCommand(removeCmd)
 	rootCmd.AddCommand(pruneCmd)
 	rootCmd.AddCommand(shellenvCmd)
+	rootCmd.AddCommand(versionCmd)
 }
 
 // Helper functions
@@ -402,3 +406,11 @@ fi
 `)
 	},
 }
+
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Show version information",
+	Run: func(cmd *cobra.Command, args []string) {
+		fmt.Printf("wt version %s\n", version)
+	},
+}