Two bugs prevented snoozing in a brand-new IMAP/JMAP account:
- IMAP flush read `payload['mailboxPath']` which doesn't exist in snooze
payloads (they use 'src'); selecting the wrong (null) mailbox caused the
operation to fail. Now uses `payload['mailboxPath'] ?? payload['src']`.
- JMAP flush had no path to create the Snoozed mailbox when the folder
didn't already exist on the server. Flush now calls `Mailbox/set` to
create it whenever `dest == 'Snoozed'` (the sentinel used when the folder
was absent at enqueue time), then substitutes the real JMAP mailbox ID.
Tests added for both code paths using a spy IMAP client and a mock JMAP
HTTP client respectively.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
