AtTime conformance stamps are the requested time (M3; identical on SQL Server). The
QuestDB test fixture prunes idle pooled connections after 1 s: undisposed per-test data
sources exhausted QuestDB's 64-connection PG-wire limit in a full run.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe