Three faults, one gesture. None of them was in `gesture/scale`, whose
`s' = s·b/a` about the pivot was right all along.
THE PIVOT. `clip/place-symbol` writes an instance's anchor, `paint/new-shape`
a drawing's, `nest/group` a new symbol's and `face-placement` the source
placement's — and `flow/freeze` wrote none for the parts underneath, so a
traced mouth turned and scaled about its own coordinate ORIGIN, which for
head-local geometry is the top-left corner of the footage. On a 320x200 stage
that put the mouth's pivot at (-234, -395), so dragging a corner outward slid
the shape about and shrank it. `pick/pivot` is `clip/center`'s rule for a node
rather than a symbol; `freeze/pivoted` applies it to every node the freeze
makes, skipping `node/measured?` — the predicate `gesture/refusal` already
refuses a hand edit by, so a pivot is written exactly where a hand can use
one. That also keeps it off `:head`, whose scale is not 1 and where an anchor
would NOT cancel out of `local!`; skipping it for drawing nothing would have
been true only by accident. Asserted in pixels: the pass moves nothing.
THE JUMP. `ui/stage`'s overlay dereferenced the document while RENDERING and
used it when the pointer went down. The store is a mutable handle behind an id
that does not change when the document does — `:paint/revision` says that, and
the overlay subscribes to neither it nor `::render/clip` — so after any edit
the next drag began from the transform the node had before the last one: still
under the press, jumping on the first pointermove. `ctx` now carries the id and
`loaded` reads at pointer-down.
THE CRASH. `gesture/values` read its channels without the tier-2 store, which
is fine until a selection lands on a dense transform — an iris follows the
gaze, a brow the raise, a head the similarity — and then `dense-at` throws and
takes the stage down, in `begin!` and again in `handles`. It takes the store
now. Kept in this commit because it is the same two functions.
`pick/bounds-of` yields a closure, as `clip/resolver` does, so an instance's
resolver is built once for a walk instead of once per frame — which is what
let `pivot` be the one walk it is rather than a separate path for instances.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
11093079de