feat: add GitHub Actions release workflow and improve docs

- Add GitHub Actions workflow for multi-platform releases
  - Build for linux/darwin on amd64/arm64
  - Auto-create GitHub Release with checksums
  - Version injection via ldflags
- Add init.d script support for install command
- Rewrite README with clearer documentation
  - Quick start guide
  - Two-node HA setup example
  - Health check configuration
  - Troubleshooting section
- Bump version to 1.2.1

🤖 Generated with [Qoder][https://qoder.com]

.github/workflows/release.yml

@@ -0,0 +1,95 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    name: Build ${{ matrix.os }}-${{ matrix.arch }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - os: linux
+            arch: amd64
+          - os: linux
+            arch: arm64
+          - os: darwin
+            arch: amd64
+          - os: darwin
+            arch: arm64
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.21'
+
+      - name: Get version
+        id: version
+        run: echo "VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+
+      - name: Build binary
+        env:
+          GOOS: ${{ matrix.os }}
+          GOARCH: ${{ matrix.arch }}
+          CGO_ENABLED: 0
+        run: |
+          mkdir -p dist
+          BINARY_NAME=go-alived-${{ matrix.os }}-${{ matrix.arch }}
+          if [ "${{ matrix.os }}" = "windows" ]; then
+            BINARY_NAME="${BINARY_NAME}.exe"
+          fi
+          go build -ldflags="-s -w -X github.com/loveuer/go-alived/internal/cmd.Version=${{ steps.version.outputs.VERSION }}" \
+            -o dist/${BINARY_NAME} .
+          
+          # Create checksum
+          cd dist && sha256sum ${BINARY_NAME} > ${BINARY_NAME}.sha256
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: go-alived-${{ matrix.os }}-${{ matrix.arch }}
+          path: dist/
+
+  release:
+    name: Create Release
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Download all artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: artifacts
+
+      - name: Prepare release files
+        run: |
+          mkdir -p release
+          find artifacts -type f -exec cp {} release/ \;
+          ls -la release/
+
+      - name: Get version
+        id: version
+        run: echo "VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+
+      - name: Create Release
+        uses: softprops/action-gh-release@v1
+        with:
+          name: Release ${{ steps.version.outputs.VERSION }}
+          draft: false
+          prerelease: ${{ contains(github.ref, '-rc') || contains(github.ref, '-beta') || contains(github.ref, '-alpha') }}
+          generate_release_notes: true
+          files: release/*
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}