When the injector's readiness grace expired it cleared the queue and logged
nothing. The failure then surfaced elsewhere as a turn-stall, which names the
wrong cause. Diagnosing CB-560 cost two live spawns and a wrong first
hypothesis for exactly this reason: the logs said "session marked failed" and
"failed send via turn-stall fallback", and neither says the message was never
typed into the pane at all.
The expiry now logs the target, the number of messages being failed, the grace
in polls and seconds, and the real cause in plain words.
The grace in seconds is derived, not written down twice: Bridged's own
INJECT_POLL_MILLIS is deleted and Injector.POLL_INTERVAL_MILLIS is the single
source, passed to every StatusPoller. A cadence change can no longer leave a
log line confidently stating the wrong duration.
Behaviour is unchanged. This is the first structured health event in the
daemon, and the foundation the fleet-health work will build on.
Dai Ha
644927636d