v0.6.0

Breaking changes

• The project was renamed from imapbackup to mailvault. Same tool, new name -- the
  PyPI name imapbackup was taken and the project now covers more than IMAP. The import
  package is renamed imapbackup -> mailvault. To keep the old ib-* commands, pin to the
  last pre-rename release, v0.5.0

• A single mailvault command replaces the three ib-mailbox / ib-archive / ib-copy
  tools. The subcommands map directly:

  • ib-mailbox folders|backup|verify -> mailvault folders|backup|verify
  • ib-copy copy [--idle] -> mailvault copy [--idle]; ib-copy folders -> mailvault copy --list-folders
  • ib-archive <sub> -> mailvault archive <sub>, with db-from-archive renamed to rebuild-db

  Global options are unified across all commands (-v/--verbose, -q/--quiet, --log-file,
  --config, --allow-exec, --job) and must precede the command. The Windows build now
  ships a single mailvault.exe instead of three ib-*.exe

Changed

• The Microsoft Graph backend is now a core dependency (msal, httpx), no longer an
  optional graph extra. Microsoft 365 is a first-class mailbox source, so mailvault always
  ships with Graph support. The mailvault[graph] install variant no longer exists -- install
  mailvault plainly

• Job configuration is validated up front: an unknown backend value, or a msgraph job
  missing tenant_id / client_id / client_secret, now fails immediately with a clear error
  naming the job. Previously an unknown backend silently fell back to IMAP and missing Graph
  credentials only surfaced deep in the backend

• copy --idle now reports a clear error when the source mailbox is not an IMAP backend,
  instead of failing later with an internal error. IDLE is an IMAP-only feature

Fixed

• Message-ID matching: a malformed Message-ID such as <> no longer crashes a run on
  Python 3.11/3.12, where CPython's email header parser raises IndexError on such values.
  The value is now treated as unusable (empty key), consistent with the behaviour on 3.13+