session-handofflisted

# Session Handoff Read current acceptance evidence and `docs/system/HANDOFF_PROTOCOL.md`. Classify the session as `IN PROGRESS`, `PHASE COMPLETE`, or `PROJECT COMPLETE`. On `PHASE COMPLETE`, update canonical owners first, write the durable phase completion report, then write the completed phase's compact `## Completion Record` pointing to that report before updating Roadmap markers. Overwrite NEXT_SESSION as volatile hot navigation rather than preserving old handoffs or turning it into a second specification. The phase completion report may preserve evidence-bounded technical detail useful to humans or later investigation. The Completion Record must remain small enough for normal progressive warm-up and must not duplicate the report. Legacy completed phases that predate separate completion reports remain valid and do not require automatic migration. For a non-trivial completed task inside an active phase, preserve only a compact task result, evidence, and decisions/issues in the phase file when later work needs them. Do not create one completion file per routine task. Use Single-Focus Continuation for `NEXT_SESSION`: one handoff prompt = one unresolved execution target. If the current task, acceptance criterion, manual verification, blocker, or other gate remains open, both `Next action` and the copyable prompt must focus only on closing that target. Do not name or preload the next queued task/phase with wording such as "then continue" or "after that start". Multiple subs