The migration re-pointed Branch/Customer at hardcoded prov-* ids before
they existed (the insert is skipped when a city already has the name),
causing Branch_cityId_fkey failures on boot. Merge now runs after the
inserts, resolves the target province by name, and relinks every table
with a City foreign key before deleting the legacy row.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>