An observer sending NUL-padded status strings had every status update rejected
by Postgres, freezing its status and telemetry. Strip them from the text fields
and the stored JSON, and warn with the fields affected.
Also drop the timestamp-clamp, empty-timestamp and malformed-IATA logs to debug;
they're expected and outnumbered inserted packets several times over.
Bucketed airtime and receive errors used MAX - MIN per bucket, so one zeroed,
replayed or garbage row counted the whole running total (e.g. 47,737 s RX in a
6 h bucket). Buckets are now summed from per-row increments with dips, stale
replays and physically impossible jumps rejected. Ingest skips uptime-only
stats and a migration deletes the rows already stored.
MrAlders0n