* Add --query to Gmail mail/sync instead of always listing in:inbox.
Callers keep the search string; default remains in:inbox.
* Document Gmail --query on the mail/sync pipeline.
* test(mail): assert Gmail --query reaches ListIDs, not only the CLI flag.
ParseCLI coverage left a hole: an empty query still has to become in:inbox
and a custom q has to be the string the client lists with.