//! plg-runtime: the support library linked into every compiled Prolog
//! binary (`libplg_runtime.a`).
//!
//! It provides the machine substrate compiled predicates call into —
//! term heap, trail, choice-point stack, generic unification, the
//! goal-only `--query` parser, solution output, and the process entry
//! point. It contains NO clause interpreter: clause control flow lives
//! in the LLVM IR that `plgc` generates (see
//! docs/design/COMPILATION_MODEL.md and docs/design/LESSONS_FROM_V1.md).