b6fcbc545f
Replaces `rayon` parallel iteration across index, rebuild, reindex, and select modules with a custom `PartitionRunner`. This introduces NUMA-aware task distribution with CPU pinning and round-robin scheduling, eliminating `Arc`, `Mutex`, and atomic synchronization primitives in favor of a flat, pre-spawned worker architecture. Error handling is simplified via `.map_err()` and the `?` operator, while progress bar updates are decoupled into dedicated callbacks.