status自动生成
会话概况：后端、场景、已发布 Kernel、节点数、修订号、内存等。
The session at a glance.
{"id": 1, "op": "status"}此操作不带字段。
backend, scene, watched, kernels (published Kernels), natives (the backend’s native operations), nodes, loaded (whether a scene is), refused (why not, when not), revision (moved by every change but running), frame (the frames committed since that revision), fusion, grants, memory (used and budget, the Host’s bytes; cold, the nodes whose outputs are let go, made again when read; where the bytes are: host, device, kept (resident Fields’ Host copies), spare, loose (Fields nothing holds), backends (what each keeps of its own) and top, the largest Fields with what holds each), versions (entelechy, api, language, ir, package)