66f1668850
Two shape fixes from the review of #92979, no behavior change: - Read imap.capabilities directly instead of the getattr(...) or () fallback — a real imaplib.IMAP4 always sets the attribute in _connect() (raising if the server sends no CAPABILITY), so the default branch only existed for a MagicMock(spec=["xatom"]) that no production path produces. Drop the test that pinned it. - Trim tests to the invariant bar: the four mock tests duplicated what test_email_imap_id_protocol.py proves on the wire (real imaplib, real socket, command order), and the phase parametrize (startup vs poll) exercised the same single _send_imap_id call site twice. Keep the three id_mode cases through the poll path. 42 tests pass; mutation check: guard removed -> the absent-ID case fails with the #39856 SELECT error, restored -> green.