#[custom_data]Expand description
Expands a named-field struct into a Serde-backed custom data type.
Generates the required Serde derives, HasTsInit, CustomDataTrait, Data conversions,
constructor, display implementation, and optional PyO3 bindings. The struct must contain
ts_event and ts_init fields.
Use #[custom_data(pyo3)] to generate Python bindings.
Use #[custom_data(pyo3, no_display)] to provide a custom display implementation.
Use stub_module = "nautilus_trader.<module>" with pyo3 to emit stub metadata.
Use #[custom_data_field(serde)] for fields requiring the generic Serde Python bridge.