applyMissingMigrations ran the entire migration SQL as one transaction,
which rolled back all changes when any statement failed (e.g. adding a
NOT NULL column to a non-empty table). Replaced with prisma db push
which compares the schema and applies only what's needed. Also added
support for importing .sql files (not just .zip) in auto-import.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>