Notebooks, Rendering Environments, sessions, kernels, notation, docs: what is built, real names, real status
Archive retired pages, promote adopted ones, stubs at names the repo links
Sessions as data: notebook answers kept and shown at once; .ipynb export (#630)
Sessions as data: notebooks keep their document (built, #630); transcripts keep a journal
Sessions as data: calls by message, the session as a replayable journal; the job store recorded as a spike