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.

Makefile

@@ -22,6 +22,7 @@ $(MKDOCS): $(VENV)/bin/activate
 		mkdocs mkdocs-material \
 		mkdocs-mermaid2-plugin \
 		mkdocs-bibtex
+	$(PIP) install --quiet --upgrade InSilicoSeq
 
 # ── obikmer binary ───────────────────────────────────────────────────────────