Install sccache during server provision

jenkins/Jenkinsfile.production-server-provision

@@ -139,6 +139,41 @@ pipeline {
               fi
             }
 
+            install_sccache() {
+              for tool_dir in "${HOME:-}/.cargo/bin" /root/.cargo/bin /usr/local/cargo/bin; do
+                if [[ -d "${tool_dir}" && ":${PATH}:" != *":${tool_dir}:"* ]]; then
+                  export PATH="${tool_dir}:${PATH}"
+                fi
+              done
+
+              if command -v sccache >/dev/null 2>&1; then
+                echo "[server-provision] sccache 已存在: $(command -v sccache)"
+                return
+              fi
+
+              if [[ -x /root/.cargo/bin/sccache ]]; then
+                echo "[server-provision] sccache 已存在: /root/.cargo/bin/sccache"
+                return
+              fi
+
+              echo "[server-provision] 未找到 sccache，准备通过 cargo install sccache 安装。"
+              if ! command -v cargo >/dev/null 2>&1; then
+                echo "[server-provision] 未找到 cargo，无法自动安装 sccache。请先安装 Rust 工具链后重跑 Server-Provision。" >&2
+                exit 1
+              fi
+
+              if [[ "${DRY_RUN}" == "true" ]]; then
+                echo "+ cargo install sccache --locked"
+                return
+              fi
+
+              cargo install sccache --locked
+              if ! command -v sccache >/dev/null 2>&1 && [[ ! -x /root/.cargo/bin/sccache ]]; then
+                echo "[server-provision] sccache 安装后仍不可用，请检查 cargo bin 目录是否在 PATH 中。" >&2
+                exit 1
+              fi
+            }
+
             render_nginx_https_config() {
               sed "s/genarrative.example.com/${SERVER_NAME}/g" deploy/nginx/genarrative.conf
             }
@@ -302,6 +337,7 @@ pipeline {
 
             run_cmd id
             install_build_dependencies
+            install_sccache
             run_cmd mkdir -p "${SPACETIME_ROOT}" "${RELEASE_ROOT}" "$(dirname "${CURRENT_LINK}")" "$(dirname "${WEB_LINK}")" /etc/genarrative /var/lib/genarrative/maintenance /var/lib/genarrative/auth
 
             if ! id spacetimedb >/dev/null 2>&1; then