The top-level prune step deleted the whole db/ folder before the
second step meant to keep db/migrations under it ever ran, so no
deploy has actually shipped migrations - the remote apply step was
running runMigrations.vbs against an empty migrations folder and
silently reporting nothing pending.

Also adds scripts/run-migrations-remote(-apply).ps1, a lighter
migrations-only counterpart to deploy-iis.ps1 for catching a
production schema up without redeploying app code - used just now to
patch prod after this bug meant it never received prior migrations.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>