Прямые и винтовые лестницы получили отдельную модель, инструменты редактора, безопасную межэтажную навигацию, вычитание из чистой площади и плоское отображение в 2.5D.
Issue: #663
User-Visible: yes
`willUpdate` keys the geometry epoch and render-lifecycle invalidation on
`changed.has('_serverCfg')`. Before #500 every body replacement went through
Lit's accessor and produced that event; the owner wrote its field directly
and the epoch stopped moving on adoption, staging and rollback — the safe
Resize smoke then measured against a stale model (Validate on c360bcc9).
`MutableConfigAdoption` now reports each replaced reference through
`onBodyReplaced`, which the card wires to `requestUpdate(field, previous)`;
echoes and identity-only changes stay silent, exactly as an unchanged
reference never fired the accessor.
Issue: #500
User-Visible: no
`src/config-adoption.ts` owns config/layout with revision and fingerprint;
the host keeps `_serverCfg`/`_cfgRev`/`_layout`/`_layoutRev` as delegates.
All seven authoritative adoptions go through `adoptAuthoritativeGated`
(backdrop readiness → continuity → adopt → profile tail); the post-write
paths (space/delete ×2, optimize_undo, import/apply) gain the gate and take
revisions from the re-read bodies. `rollbackOptimistic` moves to the owner;
plan-optimize, space copy and the vacuum writers stop assigning identity.
Issue: #500
User-Visible: no
Sergey Matyunin