iris-aiandClaude Fable 5.1
2bee0b4b53
Decided with Bryan on 2026-09-18: a child's frame is forwarded through spans, stacks and scrolls and narrowed only by what is decided from above, so rel is never a fraction of a self-sized box; placements are parts of the parent's extent in frame units from its start, so a moved extent re-places its children exactly; the placement pin becomes a symbolic length; and a local redraw asks at the offer placement without deferring. Lists the steps in order with the check for each and the failures that mean stop rather than patch. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>