Anthony f37ff8bca6 Support custom folders over IMAP ...

Key the syncer, local store and IMAP server by Tuta MailSet folder id
instead of the system folder kind, so custom (and nested) folders are
first-class.

- tuta.rs: add FolderInfo; MailBackend.list_folders enumerates system +
  custom folders via the SDK FolderSystem tree, building IMAP paths and
  RFC 6154 special-use flags; load mails by the folder's entries list.
- store.rs: folder_kind INTEGER -> folder_id TEXT, schema v2 with a
  migration that drops the cache tables and re-syncs (encrypted .eml
  files survive).
- sync.rs: MailStore keyed by folder id; the syncer enumerates the live
  folder list each cycle.
- imap/session.rs: dynamic LIST/SELECT/STATUS driven by the folder list;
  drop the hardcoded six-folder mapping.

Pulls in the SDK FolderSystem tree (tuta-repo submodule bump).

Live-tested: 9 custom folders listed and selectable over IMAP, with
headers and decrypted bodies. Not yet covered: nested-folder paths,
modified UTF-7 for non-ASCII names, labels, and IMAP MOVE/COPY.

2026-05-27 16:05:11 +02:00

..

bridge

Support custom folders over IMAP

2026-05-27 16:05:11 +02:00