chore: start transition layout — python into version-python/, scaffold version-rust/

- git mv of all existing files into version-python/ (history preserved)
- version-rust/: minimal cargo scaffold (edition 2024), no deps yet
- root AGENTS.md documents the transition rules and artifact/schema contract
- main is untouched; the python layout there stays as-is

version-python/tools/gw_inspect.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+"""Inspect gwshop catalog shape: Space Marines chapters, AoS, dedupe stats."""
+import json
+import pathlib
+from collections import Counter
+
+cat = json.loads(pathlib.Path("data/gwshop_catalog.json").read_text(encoding="utf-8"))
+entries = cat["entries"]
+
+def show(pred, label, n=6):
+    print(f"--- {label}")
+    shown = 0
+    for e in entries:
+        if pred(e):
+            p = " > ".join(x for x in (e["system"], e["group"], e["faction"], e["subfaction"], e["class"]) if x)
+            print(f"  {e['name'][:60]!r}  ->  {p}")
+            shown += 1
+            if shown >= n:
+                break
+
+show(lambda e: e["group"] == "Space Marines", "Space Marines group samples")
+show(lambda e: e["group"] == "Armies of the Imperium" and e["subfaction"], "Imperium with subfaction")
+show(lambda e: e["system"] == "Age of Sigmar", "Age of Sigmar samples", 5)
+show(lambda e: e["system"] == "The Old World", "Old World samples", 5)
+show(lambda e: e["system"] == "Other Games", "Other Games samples", 5)
+show(lambda e: e["group"] == "Unit Type", "Unit Type branch", 6)
+
+names = Counter(e["name"].casefold() for e in entries)
+dups = {n: c for n, c in names.items() if c > 1}
+print("duplicate names:", len(dups), "example:", list(dups.items())[:3])
+
+# faction-level value census for 40k
+print("--- 40k factions census")
+print(Counter(e["faction"] for e in entries if e["system"] == "Warhammer 40,000").most_common(40))