27-task plan covering 6 phases: data foundation (4 models, migration),
branch engine (BranchManager, prompt builder, API), handoff system
(park/escalate with dual-write), resolution outputs (3-output generator),
AI description pipeline, and frontend (BranchMap, ForkCard, HandoffModal,
ResolutionOutputPanel, SessionQueuePage).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
