Carry the sender's compose time as an optional "ts" (Unix seconds) in the
plaintext header JSON that rides outside the AEAD, and prefer it as the
displayed message time so both ends show the same send time regardless of when
the tx confirms. Parse "ts" leniently. On ingest, clamp: reject a "ts"
implausibly in the future vs the receive/block time (1h skew tolerated) so a
wrong/ahead peer clock can't pin messages to the bottom of a thread; a past
compose time is fine (the note buffer may broadcast a queued message later, and
a confirmed tx's block time is always >= compose time). Tests cover the
round-trip and the future-clock clamp.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
DanS
4471f54842