Defer key bundle downloads on server-initiated joins (MSCXXXX)
A server-initiated join (e.g. an auto-accepted knock) lands on all of
our user's devices in the same sync instant, so each would eagerly
download the MSC4268 room key bundle. Instead, only download it when
the server designates this device as the claimer (a new
org.matrix.mscxxxx.key_bundle_claim to-device message, only trusted
from our own user), or lazily upon the first undecryptable event in the
room. Client-initiated joins via joinRoom keep the eager behaviour.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uk8aPxHn3BHCe52L226jdG
matrix-js-sdk
af4b74bc - Defer key bundle downloads on server-initiated joins (MSCXXXX)
