New /cases/[caseNumber]/compose route ports the research analysis +
chair-position editing flow from the vanilla UI onto the Next.js
stack. Reads /api/cases/{n}/research/analysis, renders background
prose in the side column and threshold claims + issues as collapsible
cards in the main column, each with a blur-autosaved chair editor
wired through a TanStack Query mutation with optimistic cache patching
(so concurrent reads don't steal editor focus).
Handles the common "analysis not yet generated" 404 with a dedicated
empty state rather than an error card.
Phase 3 task 85 is now ready for review end-to-end.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
