OptionalalertsPrice alerts (C3). Optional + additive: Alert is already a flat,
JSON-safe shape so it persists as-is. States written before C3 omit the
field and load back with no alerts — no schema bump or migration needed.
A fired one-shot alert serializes with active: false, so it restores
disarmed (it won't immediately re-fire on the next tick).
Built-in type, or a host-registered custom series type.
OptionalpriceScaleMode?: PriceScaleModePrice-axis scale mode. Optional + additive: states written before
F1 omit it and load back as 'linear', so no schema bump needed.
Full chart snapshot — includes the candle data window. Use for workspace persistence, bug reproduction, or any case where the receiver should not re-fetch data through a transport. Typically 100 KB – 1 MB depending on buffer length.