Symptom
-------
Click Unpair on a connected account (or Delete Account). The web
action runs:
DELETE FROM whatsapp_groups WHERE account_id = ?
and Postgres rejects it:
error: update or delete on table "whatsapp_groups" violates
foreign key constraint
"reminder_run_targets_group_id_whatsapp_groups_id_fk"
on table "reminder_run_targets"
Cause
-----
\`reminder_run_targets.group_id\` had a non-null FK to
whatsapp_groups.id with no ON DELETE rule (defaults to NO ACTION /
RESTRICT). So any reminder that had ever fired pinned the group rows
in place. Unpair couldn't wipe the synced groups, the action threw,
and the row never reached \`status='unpaired'\`.
Fix
---
Mirror the pattern \`reminder_runs.reminder_id\` already uses
(migration 0005): nullable column + ON DELETE SET NULL + a
denormalised label snapshot, so historical fan-out records survive a
group wipe but stay readable.
Migration 0006:
- Drop the composite \`(run_id, group_id)\` PK; add a surrogate
\`id uuid pk default gen_random_uuid()\` since \`group_id\` can no
longer be part of the PK once it's nullable.
- Make \`group_id\` nullable.
- Re-create the FK with ON DELETE SET NULL.
- Add \`group_label text\` for the snapshot.
fire-reminder.ts now writes the group's name into \`group_label\`
on every insert path (success / failed / skipped /
account-not-connected / group-missing) so the Activity tab can keep
showing "Sent to <Group Name>" even after the group is gone.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
