//! Module: query::plan::expr::path
//! Responsibility: planner-owned compiled nested field-path contracts.
//! Does not own: runtime value-storage traversal or projection materialization.
//! Boundary: freezes normalized path segments before executor row readers use them.
///
/// CompiledPath
///
/// CompiledPath is the planner-owned nested path program used by projection
/// and predicate expression execution.
/// The string form is retained for labels and compile-time transfer into
/// `CompiledExpr` field-path leaves.
///
pub