The glossary tells a moment on a clock from a marker's, and a room that has synced from one in touch #35

Part of #26

GLOSSARY.md has moment only inside Marker ("a named moment of an arrangement"). In the room's code a moment is a point on the server's clock in milliseconds; in Waiting it is whatever clock the host uses; in the fixtures it is seconds. (ELSEWHERE, the channel a room's notes once arrived on, was removed when a room's note began to be struck as the page strikes it, so it needs no entry.) The editor's room event carries synced, which only ever goes true ("has ever synced"), beside status, which says "in touch now": keepRoom asks the first, a tile asked the first until a reviewer saw that an offline room read as fine, and the window reads status === 'synced' in patch-editor.js. "What this came from" has three shapes: Origin on a track or insert (uri, cid, linked), forkOf in a folder's groove.json (a lineage entry plus createdAt) and origin in a patch document's groove.json, which is the whole record; patch_copies.rs translates among them, and a patch document's linked ("equal to the record kept") and a track's (a flag cleared by the first edit) are two definitions of one glossary word. The ring that now carries ArpPlayed::Replaced off the audio thread is named for arpeggios.

Done when the glossary has entries for a moment on a clock (which clock, in which unit, in which code), for the two room states under two names, and one entry for what a copy came from that says which of the three shapes holds it where; and the names in Groove follow: the room's own moments say their clock, the window reads nothing but status, and the ring off the audio thread is named for what it carries. Left out: the editor's event names, which are the editor's; one type for "copied from" across a track and a document, a change of its own once the glossary has the word.