The console created Reports, the CLI that makes the first administrator did not,
so that account had no folder for DMARC and TLS-RPT reports. The list now lives
in one SQL function, provision_default_folders (migration 0014), which both call.
The same migration reconciles what the two paths had left wrong in existing
mailboxes: folder counters and the mailbox's used bytes are recomputed from the
rows (only where they differ, so it is safe to run again).
create-admin can now be tested: fail() throws instead of exiting, and the command
runs only when invoked as one. The new test fails on the old code (no Reports).
