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.

benchmark/downloads.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+assemblies=(
+    GCF_000005845.2
+    GCF_000010245.2
+    GCF_000007445.1
+    GCF_000006665.1
+
+    GCF_000006945.2
+    GCF_000195995.1
+    GCF_000009505.1
+    GCF_000026565.1
+
+    GCF_000016305.1
+    GCF_000019965.1
+    GCF_000240185.1
+    GCF_000742135.1
+
+    GCF_000069965.1
+    GCF_000022565.1
+    GCF_000306885.1
+    GCF_003013715.1
+
+    GCF_000009045.1
+    GCF_000009825.1
+    GCF_000022445.1
+    GCF_000834255.1
+)
+
+mkdir -p genomes
+
+for acc in "${assemblies[@]}"; do
+    echo "Downloading ${acc}"
+
+    datasets download genome accession "${acc}" \
+        --include genome \
+        --filename "${acc}.zip"
+
+    unzip -q "${acc}.zip" -d "${acc}"
+    find "${acc}" -name "*.fna" |
+        while read file; do
+            obiconvert -Z ${file} >genomes/$(basename ${file}).gz
+        done
+
+    rm -rf "${acc}" "${acc}.zip"
+done