feat(deploy): add deployment script and update Docker docs

- Add deploy.sh for automated Docker build and push to private registry
- Lowercase Docker image name to comply with registry requirements
- Update README with concrete Docker run examples and configuration

deploy.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+set -e
+
+REGISTRY="${GITEA_REGISTRY:-git.msksbr.com}"
+USERNAME="${GITEA_USERNAME:-msksbr}"
+IMAGE="$REGISTRY/$USERNAME/bookmgr"
+VERSION=$(grep '^version' build.gradle.kts | head -1 | sed 's/.*"\(.*\)".*/\1/')
+
+echo ">>> 版本: $VERSION"
+echo ">>> 镜像: $IMAGE"
+
+# 1. 构建 jar + 生成 Dockerfile
+echo ">>> 构建..."
+./gradlew clean build dockerCreateDockerfile
+
+# 2. 构建镜像
+echo ">>> 构建镜像..."
+docker build \
+  -t "$IMAGE:$VERSION" \
+  -t "$IMAGE:latest" \
+  build/docker/
+
+# 3. 推送镜像
+echo ">>> 推送镜像..."
+docker push "$IMAGE:$VERSION"
+docker push "$IMAGE:latest"
+
+echo ""
+echo "完成！"
+echo "  镜像: $IMAGE:$VERSION"
+echo "  jar:  build/libs/book<gr-$VERSION.jar"
+echo ""
+echo "接下来手动操作："
+echo "  1. 去 Gitea 创建 Release，版本号填 v$VERSION"
+echo "  2. 上传 build/libs/bookMgr-$VERSION.jar"
+echo "  3. 上传 API 文档"