//! Helper for constructing TreeConfig from SGBT configuration.
use SGBTConfig;
/// Build a [`TreeConfig`] from an [`SGBTConfig`], threading every knob.
///
/// Every SGBT construction site (ctor, grow, restore) must call this function
/// rather than constructing `TreeConfig` inline. This eliminates the entire
/// class of "knob added to SGBTConfig but missed in one construction path" bugs.
///
/// The `leaf_decay_alpha` (computed from `leaf_half_life`) and `seed` (per-step
/// offset) are left at their defaults — callers must set them via `.leaf_decay_alpha_opt()`
/// and `.seed()` after calling this function.
pub