Updated memory guidelines and feedback docs to explicitly classify intra-partition phases as parallel, correcting prior assumptions of sequential execution. Refactored merge_layer.rs to wrap column builders in Arc<Mutex<ColBuilder>> and use Arc::try_unwrap for safe concurrent access, eliminating race conditions and preventing double-closes during pass2.
Replace in-memory hashing with a disk-backed external merge sort and `PersistentCompactIntVec` to drastically reduce peak RAM. Unify both phases using a custom `PtrHash` MPHF, eliminating `GOFunction` and `boomphf`. Introduce a concrete three-step `count_partition()` pipeline with adaptive chunk sizing based on available system memory. Update dependencies to `memmap2`, `ptr_hash`, and `obicompactvec`. Additionally, document strict genomics-only memory constraints and enforce an architectural feedback workflow requiring explicit user authorization before structural changes.
Eric Coissac