Migration 0073 adds a UNIQUE constraint on
(user_id, medication_id, scheduled_for, source) for
medication_intake_events. Pre-fix the table only had an INDEX on those
three columns, so the two newly-projecting routes — the intake route
(PR #191) and the dashboard summary route (v1.4.39.4) — could pass
their existence probes simultaneously and mint the same REMINDER row
twice when the iOS app hydrates both endpoints in parallel.
`source` is in the key so the reminder worker's REMINDER row doesn't
collide with manual user inserts (WEB / TELEGRAM / IMPORT) on the
same slot — distinct intake sources at the same scheduled instant are
a legitimate shape (Telegram-bot logged take + a Web-UI correction on
the same dose).
The legacy (user_id, medication_id, scheduled_for) index stays in
place because most reads filter on those three columns without
caring about source. The new constraint becomes the structural
backstop; the createMany skipDuplicates: true flag added in the two
routes is the defense-in-depth layer.
Additive only. DO $$ … EXCEPTION-on-duplicate guard mirrors 0067 /
0071 so re-runs are idempotent.
Marc-André Bombeck
61f2dca421