feat: add benchmark pipeline, expose APIs, and enforce strict paths

Introduces a Make-based orchestration for simulating, indexing, merging, filtering, and verifying k-mer counts and presence. Exposes internal builder and iterator APIs publicly, enforces mandatory leading slashes for predicate patterns, registers the `obitaxonomy` crate, and updates tooling configurations alongside documentation.

mkdocs.yml

@@ -53,6 +53,7 @@ nav:
       - Merge parallelism & memory: implementation/merge_parallelism.md
       - Kmer filtering: implementation/filtering.md
       - Select command: implementation/select.md
+      - obitaxonomy crate: implementation/obitaxonomy.md
   - Architecture:
       - Sequences: architecture/sequences/invariant.md
       - Kmer index: architecture/index_architecture.md