Closed bars only, ascending by time.
Coverage start: the from of the request that filled this entry.
When the bar AFTER this entry's coverage closes, so freshness needs no re-resolve. Null is impossible here: an entry whose bars have no knowable close is never stored in the first place.
Wall clock (ms) at store time, for TTL.
Coverage end (inclusive): the last instant this entry is complete to.
OptionalversionPersisted schema version. Missing means the compatible legacy schema.
One cached series. Plain JSON: safe to persist as-is.