Development record

The prompt router's root-commit lookup (boundedRootCommit) is a full-history rev-list under a 2 s cap. On a very large repository without a commit-graph it could exceed that cap on every prompt, so the live drain and the tied-note recall would skip every prompt, each with a stderr line, and staged transcripts would never drain there. It measured 0.01 s on this repository (7,873 commits), so the failure is projected, not observed.