Module resolver 

三层配置解析器

L0 默认值 → L1 配置文件 → L2 动态覆盖（API 写入） 最终有效值 = L2 ?? L1 ?? L0

Structs

ResolvedField

A resolved config field with all three layers visible.

Functions

apply_overrides

Apply L2 overrides onto a TOML value tree, then deserialize to ActrixConfig.

resolve_all

Resolve all config fields across all services.

resolve_for_service

Resolve all config fields for a given service.