merge work/merge-89-90 into main (Create-string #89/#90 + PR #97 fixes)

Reconciles two independent lines of work that both touched Review.svelte,
MultiSelect.svelte, and the thickness band:

- main's PR #97 (client-side thicknessBand.ts + MultiSelect names/commit +
  syncSelects DOM race fix + box-sizing CSS)
- work/merge-89-90 (server-side thickness band in thickness_band.py,
  Create-string #89, metadata_locked dropped, photo strip, wood primary)

Canonical resolution: the band is SERVER-side (hidden from UI, sent to Woo
on publish), so the client-side thicknessBand.ts + read-only band display
are removed from Review.svelte; PR #97's syncSelects() and box-sizing CSS
are preserved (orthogonal fixes). MultiSelect takes selectedSummary from
woodPrimary.ts (names in closed state) + the ms-count testid + onDestroy
timer cleanup; duplicate close()/summary definitions dropped.

Gates: backend 117/117, unit 88/88, tsc clean, e2e 6/6 (m3-create +
photo-strip).

docs/contracts/UX.md

@@ -12,7 +12,7 @@ Status: SPEC · 2026-09-18. Presentation spec for the mill-owner flow on phone a
 | CAPTURE-40, CAPTURE-41, CAPTURE-45, CAPTURE-50, CAPTURE-55 | sheet/sensitivity controls, overlay, retake |
 | CAPTURE-60, CAPTURE-65, CAPTURE-70, CAPTURE-80, CAPTURE-85, CAPTURE-90 | axis, entry, derived numbers |
 | CAPTURE-105, CAPTURE-130, CAPTURE-135, CAPTURE-141, CAPTURE-145, CAPTURE-150, CAPTURE-155 | crop guard, lineup order, upload, preview/controls, failure |
-| METADATA-10, METADATA-15, METADATA-30 | required taxonomy fields and cardinality |
+| METADATA-10, METADATA-15, METADATA-30, QUALITY-95 | required taxonomy fields and cardinality; the thickness band is derived from the measurement, not picked |
 | METADATA-45, METADATA-55, METADATA-110 | pre-fill, Generate text availability |
 | PUBLISH-5, PUBLISH-10, PUBLISH-15, PUBLISH-20, PUBLISH-25, PUBLISH-30, PUBLISH-35, PUBLISH-36, PUBLISH-37, PUBLISH-38, PUBLISH-50 | publish sequence, outcomes and messaging |
 | REVIEW-5, REVIEW-10, REVIEW-15, REVIEW-20, REVIEW-25, REVIEW-30, REVIEW-40, REVIEW-45, REVIEW-50 | ready set, gating, fields, limits |
@@ -62,6 +62,9 @@ Cites REVIEW-5, REVIEW-15, REVIEW-20, METADATA-45.
   (`REVIEW-5`) via that derived value.
 - **Primary category.** The owner declares one primary wood category and any secondary ones; the
   default is the first selected.
+- **Thickness band is derived and not shown.** The measured thickness bands up into the synced Woo
+  band server-side (`METADATA-15`, `QUALITY-95`); Review carries no thickness-band control and no
+  read-only echo of it. The derived band is stored on the slab and sent to the store at publish.
 - **Inline nudges.** Every empty required field shows an inline nudge as the owner works; there is
   no single submit-time gap list.
 - **Calculated fields.** Widths, sqft, and bdft are read-only and not overridable.