Review follow-up on #93959:
1. Partial-failure window: if the row commits but the transcript copy or
title write fails, the durable-but-empty child defeated the lazy
first-prompt fallback (_ensure_session_db_row is INSERT OR IGNORE), so
the renderer fail-latched on a transcript-less session again. The seed
block now compensates: delete just this child so the lazy path can
retry cleanly. Disk-full is exempt — deleting data on a full disk makes
things worse.
2. Silent degradation: the best-effort catch now logs at WARNING with
exc_info instead of DEBUG, so a regression in this user-facing path is
observable without enabling debug logs.
Tests: compensation deletes the half-written row and preserves
pending_title; disk-full keeps the row and surfaces the WARNING.
ClintonEmok
78eb4ebbfc