Don't let telemetry/logging cook the loop under a storm.
- lib/log-coalescer.js: dedup+count high-frequency lines, flush ONE summarized line per
key per window ("[loop-lag] band=critical (x47 in 30s)"). Bounded buffer (auto-flush
at MAX_KEYS). Applied to the loop-lag "still loaded" line (band CHANGES stay immediate),
the per-request OTA check line, and "Device reconnected".
- loop-lag: event_loop_lag rows are BUFFERED and batch-inserted on a flush interval
(was a synchronous INSERT per sample); the buffer is bounded (drop-oldest). Its
retention prune now rides the Item-A chunkedDelete so this table can never repeat the
status_log bloat-then-freeze. /api/status still reads in-memory current (real-time
band unaffected).
- Bounded the previously un-evicted per-device Maps: content-ack limiter gets an idle
sweep (started in server.js); status-log-writer.lastWritten is capped (drop-oldest;
it only suppresses a redundant consecutive row, so eviction is safe).
Tests: N identical lines -> one counted line; single line verbatim; coalescer buffer
bounded under a distinct-key flood; content-ack Map swept of idle buckets.
loop-lag-integration updated for the batched-insert cadence. Suite 266/266.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
