Add GW webshop catalog source (Algolia): dlphelper.gwshop + full dump

- warhammer.com shop HTML/listing endpoints are behind AWS WAF (405/202
  goku challenge) for non-browser clients; findings recorded in AGENTS.md
- the shop search runs on Algolia; public search-only key lets us dump the
  whole product index with plain requests (no browser, no captcha)
- gwshop.py: credential loading (env or gitignored algolia.json), index
  listing, facet-partitioned full retrieval (search-only key cannot /browse
  and pagination caps at 1000, so the index is partitioned on the
  GameSystemsRoot hierarchy facet), normalization into the sorter's
  source-agnostic catalog schema (system/group/faction/subfaction/class)
- data/gwshop_catalog.json: snapshot of prod-lazarus-product-en-ww,
  3491 unique products, every product with full hierarchy path
- tools/: one-shot browse + catalog builder + shape inspector

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))