feat(rust): difflib port + taxonomy data dump

- src/difflib.rs: faithful port of CPython difflib.SequenceMatcher
  (Ratcliff/Obershelp ratio incl. real_quick_ratio/quick_ratio and autojunk),
  validated against python-computed test vectors with exact float equality
- data/warhammer_data.json: taxonomy tables dumped from the python module
  (tools/dump_warhammer_data.py), parsed order-preserving in
  src/warhammer_data.rs (python dict insert-order + last-value-wins semantics)
- deps for the module ports: clap, reqwest, url, base64, regex, sha2, hex,
  sevenz-rust2, unrar, zip, indexmap, rand, rpassword

version-rust/tools/dump_warhammer_data.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+"""Regenerate version-rust/data/warhammer_data.json from the python module.
+
+Run from the repo root (the version containing the python layout):
+
+    python3 version-rust/tools/dump_warhammer_data.py
+
+The Rust rewrite parses this file (src/warhammer_data.rs) instead of holding
+a hand-transcribed copy of the taxonomy tables, so the two versions work
+from byte-identical data.
+"""
+
+import json
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent.parent / "version-python"))
+
+from dlphelper import warhammer_data as w  # noqa: E402
+
+out = Path(__file__).resolve().parent.parent / "data" / "warhammer_data.json"
+
+payload = {
+    "systems": w.SYSTEMS,
+    "classes": [[name, keywords] for name, keywords in w.CLASSES],
+    "group_of_faction": w.GROUP_OF_FACTION,
+}
+out.write_text(json.dumps(payload, ensure_ascii=False, indent=1), encoding="utf-8")
+print(f"wrote {out} ({out.stat().st_size} bytes)")