P2: test fourSides numbering against GEOMETRY per side (L cy↓, R y↑,
T x↑, B x↓) with a de-overlap drift tolerance, not label-emission order
(which numbering walks, so it could never fail). P3: assert every
pairedRows leader carries polys.length===2. Both mutation-tested: a
reversed side sort and a dropped polys each make the gate FAIL.
Clear check:no-fleet-names (neutral wording for the classic4 reference,
the vendored-fork note, the browser-budget comment, the gate's format
comment and the package.json description). Fix pairedRows leaders[].polys
(was null on every leader — store fork.polys; drop dead polysForCount).
Tie-break ids by code unit (cmpId), not localeCompare, for byte-identity
across runtimes/locales. Harden the gate: assert the fourSides side
sequence L<T<R<B and monotone numbering within each side (by label
emission order), and recount pins-outside-state and pairedRows crossings
from the OUTPUT, not from stats.
New library/packet/circularLayout.js: ring order, leader routing,
numbered four-sides and paired-row forks as a single pure, Worker-safe
module (geometry in, geometry out; no SVG, no DOM, deterministic). Modes
sideLanes (today's L/R), fourSides (numbered, no leaders) and pairedRows
(two leaders per row). measure/slotOf and placePinsInState/forkRoute are
injected; forkRoute falls back to a vendored copy until fork-leaders is
on this tree. Adds check:circular-layout (frozen 855-pin 60x96 fixture:
ring order, 0 dupes, 0 pins-outside-state, 0 crossings on paired rows,
determinism, a poison, and a node time/heap budget).
