ci: add multi-arch dev image build script

- deploy/docker/build-dev.sh + make image-dev: linux/amd64+arm64 build & push,
  dev/dev-<sha>/dev-<date> tags, registry inline cache, auto create buildx builder
- PUSH=0 falls back to host-arch build with --load for local verification
- verified end-to-end (PUSH=0): container frontend build, CGO-free cross compile,
  upx pack 31.7MB->11.8MB, image smoke test 200

deploy/docker/build-dev.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env sh
+# 构建 dev 镜像：默认多平台(amd64/arm64)并推送，PUSH=0 时按本机架构构建并加载到本地
+#
+# 用法：
+#   sh deploy/docker/build-dev.sh                 # 多平台构建并推送 dev 标签
+#   PUSH=0 sh deploy/docker/build-dev.sh          # 本机架构构建 --load，仅本地
+#   REGISTRY_IMAGE=demo/openteam PLATFORMS=linux/amd64 sh deploy/docker/build-dev.sh
+set -e
+
+cd "$(dirname "$0")/../.."
+
+REGISTRY_IMAGE=${REGISTRY_IMAGE:-mirrors2/opencatd-open}
+PLATFORMS=${PLATFORMS:-linux/amd64,linux/arm64}
+BUILDER=${BUILDER:-xbuilder}
+PUSH=${PUSH:-1}
+DOCKERFILE=${DOCKERFILE:-deploy/docker/Dockerfile}
+
+SHORT_SHA=$(git rev-parse --short HEAD 2>/dev/null || echo unknown)
+DATE_TAG=$(date +%Y%m%d)
+
+# 确保 buildx 容器构建器存在（默认 docker driver 不支持多平台）
+docker buildx inspect "$BUILDER" >/dev/null 2>&1 || docker buildx create --name "$BUILDER" --driver docker-container >/dev/null
+
+TAGS="-t $REGISTRY_IMAGE:dev -t $REGISTRY_IMAGE:dev-$SHORT_SHA -t $REGISTRY_IMAGE:dev-$DATE_TAG"
+
+if [ "$PUSH" = "1" ]; then
+  echo ">>> 多平台构建并推送: $PLATFORMS"
+  # shellcheck disable=SC2086
+  docker buildx build \
+    --builder "$BUILDER" \
+    --platform "$PLATFORMS" \
+    $TAGS \
+    --cache-from type=registry,ref="$REGISTRY_IMAGE:dev" \
+    --cache-to type=inline \
+    -f "$DOCKERFILE" \
+    . --push
+  echo ">>> 已推送: $REGISTRY_IMAGE:dev (dev-$SHORT_SHA, dev-$DATE_TAG)"
+else
+  HOST_ARCH=$(docker version -f '{{.Server.Arch}}')
+  echo ">>> 本机架构构建并加载: linux/$HOST_ARCH"
+  docker buildx build \
+    --builder "$BUILDER" \
+    --platform "linux/$HOST_ARCH" \
+    $TAGS \
+    -f "$DOCKERFILE" \
+    . --load
+  echo ">>> 已加载本地镜像: $REGISTRY_IMAGE:dev (dev-$SHORT_SHA, dev-$DATE_TAG)"
+fi