Add standalone desktop workflow

ops/build-release.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+
+set -eu
+
+ROOT_DIR=$(CDPATH= cd -- "$(dirname "$0")/.." && pwd)
+RELEASE_DIR="${ROOT_DIR}/release"
+CACHE_DIR="${RELEASE_DIR}/.gocache"
+VERSION=${VERSION:-$(git -C "${ROOT_DIR}" describe --tags --always 2>/dev/null || echo dev)}
+
+build_target() {
+    goos="$1"
+    goarch="$2"
+    output_name="$3"
+
+    echo "building ${goos}/${goarch} -> ${output_name}"
+    env \
+        GOCACHE="${CACHE_DIR}" \
+        GOOS="${goos}" \
+        GOARCH="${goarch}" \
+        go build \
+        -ldflags "-X main.Version=${VERSION}" \
+        -o "${RELEASE_DIR}/${output_name}" \
+        ./cmd/jukebox
+}
+
+command -v go >/dev/null 2>&1 || {
+    echo "error: go not found in PATH" >&2
+    exit 1
+}
+
+mkdir -p "${RELEASE_DIR}" "${CACHE_DIR}"
+
+build_target darwin arm64 jukebox-darwin-arm64
+build_target windows 386 jukebox-windows-386.exe
+
+echo ""
+echo "artifacts:"
+echo "  ${RELEASE_DIR}/jukebox-darwin-arm64"
+echo "  ${RELEASE_DIR}/jukebox-windows-386.exe"