Add flock-based locking to prevent concurrent service operations

source/agent-remote/ds_run.sh

@@ -77,6 +77,9 @@ export TEMPLATE_PATH="${DROPSHELL_DIR}/services/${SERVICE}/template"
 [[ -f "${DROPSHELL_DIR}/server_info.env" ]] || _die "Missing ${DROPSHELL_DIR}/server_info.env"
 [[ -d "${CONFIG_PATH}" ]] || _die "Service '${SERVICE}' does not exist on server (missing ${CONFIG_PATH})"
 
+# -- Acquire exclusive lock (released automatically on exit) --
+_lock_service "${DROPSHELL_DIR}/services/${SERVICE}"
+
 # -- Load template info (template defaults, loaded first) --
 export TEMPLATE_INFO_ENV="${TEMPLATE_PATH}/template_info.env"
 if [[ ! -f "${TEMPLATE_INFO_ENV}" ]]; then