Browser editing and menu fixes; column auto-fit. User requested merge and deployment on 2026-09-17.
Candidate: 95ba60076977e783a47aab8284e16370764e65a9, branch fix/cell-editing.
Changes: cell editor inherits cell text formatting; Cut defers source clearing until successful atomic paste; formula editing accepts clicked/dragged references; WebKit menu focus no longer hides form buttons before activation; keyboard menu activation and resize fields work; column divider double-click and Format > Auto-fit columns fit selected columns individually; manual multi-column resizing persists all columns.
Independent source review: GPT-6 Astra. All reported findings fixed and covered by browser checks. Final review found no blocking source issues.
Validation: exact candidate CI passed (vet, format, build, migration, Go suite, race). Chromium and WebKit component audits each exercised 56 menu actions plus keyboard submission, resize fields, Escape and outside click. Both engines passed auto-fit single/multiple columns, below-viewport formatted values, reload persistence, bounds, failure/retry, and manual group resize. Clipboard/formula/editor regressions passed in Chromium.
Deployment review pending: candidate is being deployed only to the existing isolated overnight-sheets.bds.oncarlos.com canary, channel canary/overnight-batch, environment overnight-batch. The previous synthetic test session was signed out and deleted, so fresh ordinary canary sign-in is needed for authenticated browser review. Production is unchanged. No fixture bootstrap or authentication bypass is being introduced.