Per sub-project-2 plan Task 11 / spec §8.1. proposed_records filter and approve()
return an approved copy via dataclasses.replace (no in-place mutation), with
optional coordinate/rationale override and an injected reviewed_at timestamp.
Pure, no I/O, no clock.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>