DeliveryStatus showed whatever mEvent.status was at the last timeline
re-render, and a local echo's status changes (SENDING → SENT → confirmed,
NOT_SENT → retried) only emit event-level events, so the last message in
a quiet room kept "Sending..." (or a stale "Failed to send. Click to
retry" after an outbox retry) indefinitely. It now re-renders on
MatrixEventEvent.Status / LocalEventIdReplaced.
Not browser-verified in this change (checks: tsc, unit tests, eslint).
Fixes#306
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5