Interface CronEntry

Handler invoked on the first parallel tick to reach a new boundary.

Candle interval at whose boundaries the handler fires. Same scale as CandleInterval used by Interval and Cache: "1m" | "5m" | "1h" | "1d" etc.

If omitted, the entry switches to fire-once mode: the handler is invoked on the very first matching tick (no boundary check) and never again. If the handler throws, the entry is not marked as fired and will retry on the next tick.

Unique name of the entry. Used as the dedup key on register (re-registering the same name replaces the previous entry) and as part of the singleshot coordination key.

Must be non-empty and must not contain : — : is reserved as the slot-key segment separator and would otherwise create ambiguity between global and fan-out fire-once keys.

Symbol whitelist that doubles as the fan-out switch.

• Empty/undefined → global singleshot: across all parallel backtests the handler runs once per boundary. The first symbol to reach the boundary opens the slot; others await the same promise.
• Non-empty → per-symbol fan-out: ticks whose symbol is not in the list are skipped, and ticks whose symbol is in the list each open their own slot. The handler runs once per whitelisted symbol per boundary.

The same rule applies in fire-once mode: global → handler runs once total; fan-out → once per whitelisted symbol.

Each symbol must not contain : (same reason as CronEntry.name).