What This Incident Justifies Adding to CLAUDE.md

By the end of the case study, the team has learned several concrete things: the export pipeline's keyset pagination needs a tiebreaker column to be safe under concurrent writes; at least two pipelines (export-transactions and export-audit-log) shared a copy-pasted cursor implementation; a debug script (scripts/replay-export.ts) broke silently when the cursor's shape changed because it wasn't caught by the test suite; and a nightly routine now watches for export row-count discrepancies.

1. Write the specific CLAUDE.md additions you'd make as a result of this incident — actual proposed lines, not just categories.
2. For each addition, justify it against the "would removing this cause Claude to make mistakes?" test from the best-practices guidance.
3. Identify at least two tempting additions related to this incident that should NOT go in CLAUDE.md, and say where each belongs instead (a hook, a skill, nowhere).