Captures end-of-session state after Phases 1-2-4 merge: current
architecture, shipped commits, three documented open items
(retrieval-augmented routing test before Phase 5; non-atomic cache
write; log rotation), unscheduled-but-ready items (weekly digest + log
prune), telemetry collection window, roadmap status, and a pickup
prompt template for the next session.
Dated filename so future handoffs can coexist without overwriting.
