Closes criterion 5 of ScadaBridge/docs/known-issues/2026-07-20-localdb-disk-io-
error-under-load.md §9: Phase 1 shipped only correctness and convergence tests,
so nothing exercised many pooled per-operation connections writing a REGISTERED
table (capture trigger + zb_hlc_next UDF) concurrently — which is exactly the
shape the ScadaBridge site nodes run under load.
8 writers x 250 inserts, one fresh pooled connection per operation, with
concurrent readers churning the pool and the WAL index throughout. Asserts both
that every write lands and that the oplog captured each exactly once, so a
trigger that dropped or double-counted under contention fails it.
Written during the 2026-07-20 disk-I/O incident investigation and left
uncommitted; the incident itself was root-caused to host-side sqlite3 access on
a bind-mounted WAL database, not a library defect.
Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
Joseph Doherty
10d076a9da