Add release workflow

Author: Mayyhem

.github/workflows/release.yml

@@ -0,0 +1,113 @@
+name: Release
+
+on:
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: "Release tag (e.g. v2.0.0). Must match v<major>.<minor>.<patch>[-suffix]."
+        required: true
+        type: string
+      release_notes:
+        description: "Release notes body (markdown). Optional."
+        required: false
+        type: string
+
+permissions:
+  contents: write
+
+concurrency:
+  group: release-${{ inputs.tag }}
+  cancel-in-progress: false
+
+jobs:
+  validate:
+    name: Validate inputs
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Check tag format
+        run: |
+          echo "${{ inputs.tag }}" | grep -Eq '^v[0-9]+\.[0-9]+\.[0-9]+(-[A-Za-z0-9.]+)?$' \
+            || { echo "Invalid tag: ${{ inputs.tag }}"; exit 1; }
+      - name: Ensure tag does not already exist
+        run: |
+          if git rev-parse "refs/tags/${{ inputs.tag }}" >/dev/null 2>&1; then
+            echo "Tag ${{ inputs.tag }} already exists — pick a new one."
+            exit 1
+          fi
+
+  build:
+    name: Build ${{ matrix.goos }}/${{ matrix.goarch }}
+    needs: validate
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: true
+      matrix:
+        include:
+          - { goos: linux,   goarch: amd64, ext: "" }
+          - { goos: linux,   goarch: arm64, ext: "" }
+          - { goos: windows, goarch: amd64, ext: ".exe" }
+          - { goos: windows, goarch: arm64, ext: ".exe" }
+          - { goos: darwin,  goarch: amd64, ext: "" }
+          - { goos: darwin,  goarch: arm64, ext: "" }
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: "go.mod"
+          cache: true
+
+      - name: Build
+        env:
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+          CGO_ENABLED: "0"
+        run: |
+          set -euo pipefail
+          VERSION="${{ inputs.tag }}"
+          VERSION_NO_V="${VERSION#v}"
+          OUT="mssqlhound-${VERSION}-${GOOS}-${GOARCH}${{ matrix.ext }}"
+          mkdir -p dist
+          go build -trimpath \
+            -ldflags "-s -w -X main.version=${VERSION_NO_V}" \
+            -o "dist/${OUT}" ./cmd/mssqlhound
+          ls -lh dist/
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: mssqlhound-${{ matrix.goos }}-${{ matrix.goarch }}
+          path: dist/*
+          if-no-files-found: error
+          retention-days: 7
+
+  release:
+    name: Create GitHub Release
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/download-artifact@v4
+        with:
+          path: dist
+          merge-multiple: true
+
+      - name: Generate SHA256 checksums
+        working-directory: dist
+        run: |
+          sha256sum * > checksums.txt
+          echo "--- checksums.txt ---"
+          cat checksums.txt
+
+      - name: Create release and upload assets
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: ${{ inputs.tag }}
+          name: ${{ inputs.tag }}
+          body: ${{ inputs.release_notes }}
+          target_commitish: ${{ github.sha }}
+          draft: false
+          prerelease: false
+          files: dist/*
+          fail_on_unmatched_files: true