Replaces the global Rayon pool with per-NUMA-node thread pools that pin worker threads to their respective nodes, leveraging Linux first-touch allocation to reduce cross-NUMA memory contention and improve cache locality. Integrates the `hwlocality` crate with a vendored build, includes graceful fallbacks for single-socket or non-Linux systems, and updates dependency constraints. Also adds installation and architecture documentation, and corrects parallelism detection in the partitioner.