Two related issues caught in live verification:
1. Coinbase's sequence_num is connection-global (not per-product). Previous
per-product tracking flagged every cross-product frame as a gap.
2. Even after switching to global tracking, gaps still occur regularly under
normal operation (Coinbase's exact sequencing pattern across channels is
not strictly seq+1 frame-to-frame). Treating gaps as fatal kills the
ReadLoop in seconds, never giving the minute aggregator a chance to cross
a boundary, so btc_eth_minute stays empty.
Resolution: rewrite Sequencer for a single global counter and downgrade
gap-detection to a non-fatal Warn. ReadLoop continues; (symbol, ts) PK on
btc_eth_ticks is the safety net for any duplicate replay. Includes a
diagnostic log on loop exit (handleConn) for ops visibility.
d4995c1258