refactor: rename obikpartitionner crate to obikpartition

Update Cargo manifests, dependency paths, and Rust imports across the workspace to reflect the `obikpartitionner` to `obikpartition` rename. Synchronize architecture and implementation documentation with the new module structure. Fix minor syntax issues in test assertions to ensure compilation compatibility. No behavioral or API changes are introduced.

src/obikphylo/src/siblings/build.rs

@@ -4,7 +4,7 @@ use std::sync::atomic::Ordering;
 
 use rayon::prelude::*;
 
-use obikpartitionner::KmerPartitions;
+use obikpartition::KmerPartitions;
 use obikseq::CanonicalKmer;
 use obilayeredmap::MphfLayer;
 use obilayeredmap::meta::IndexMode;