`docs/lane-handoff.md`, after `timing-handoff.md`'s shape, because the next
thread starts cold and the expensive part of that is not the code — it is the
decisions that were argued out and would otherwise be argued again.
So the section that matters most is the one listing what NOT to re-litigate:
the shot length is authored, placing ripples and overwrite is blank-then-place,
a position inside a cel refuses and names split, a correction has no time space
of its own, a layer's values are a channel, a conflict is not a problem, and a
command refuses rather than guesses. Each of those is a paragraph here and a
commit message in full.
Then the vocabulary, since it was settled one commit ago and the old words are
still in this repository's history: instance, cel, lane, drawing, and placement
for where a node sits only. With the warning that `exposure` still means the
`:expose` grid and always did.
Then the mechanisms that keep paying out — `:span` in the node's own frames
above all, which is why split, trim and blank cost almost nothing — the known
gaps, and how to run the suites, including that a release build clobbers the dev
bundle the browser tests need.
Recommended next piece is the cel sheet: it needs no new model, and it is the
first real evidence the document is not shaped by the timeline that grew up
with it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>