Domain-specific detail (symbol, account, counts, sample, errorMsg, …).
OptionalcidCorrelation id pairing an operation's start with its terminus.
OptionaldurationWall-clock duration of the operation, in milliseconds (set on the terminus line).
OptionaltriggerWhat initiated the operation (cron name, route, event) — lets an AI trace up the stack.
Core, strictly-typed flight-recorder extras. The named fields are fixed so an AI can grep them reliably; arbitrary extra keys carry domain detail.