StampLogin appends one login_events row per user per day via an atomic
INSERT ... SELECT ... WHERE NOT EXISTS, run through withUser so the throttle
probe is itself RLS-scoped to the caller. DeleteUser now deletes login_events
explicitly (no FK = no cascade — the summary_actions footgun, repeated).
Extends the two-user RLS isolation proof and the delete-account proof to cover
login_events, and adds throttle / new-day / user-scoping tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
