refactor: group scripts into walker/ wikigen/ bundle/

Organize the 16 loose scripts by concern:
  walker/  -- .wbt save tooling (sand, build_wbt, walker_hashes,
              harvest_hashes, recover_key)
  wikigen/ -- MediaWiki page generators (make_*_wiki, render_wiki)
  bundle/  -- Unity/Odin asset extraction (unitybundle, odin_read,
              extract_*, loot_probe, dump_loot_bytes)

The only cross-script imports (build_wbt->walker_hashes,
extract_loot->odin_read) live within the same folder, so each
script's dir on sys.path[0] keeps them resolving with no code
changes. All data paths are absolute, so the moves don't affect
I/O. Named the code dir wikigen/ to avoid colliding with the
generated wiki/ output dir; ignore the regenerable wiki_site/ render.

bundle/extract_data.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python3
+"""Extract SAND MonoBehaviour data (loot tables, crafting graph, …) using IL2CPP typetrees.
+
+Builds a UnityPy TypeTreeGenerator from GameAssembly.dll + global-metadata.dat (Unity
+6000.0.40f1), loads the relevant bundles into one environment so PPtr references resolve,
+reads each MonoBehaviour against its generated typetree, and rewrites PPtrs as the target's
+m_Name where known. Output: structured JSON in extracted/.
+"""
+import os, sys, json, UnityPy
+from UnityPy.helpers.TypeTreeGenerator import TypeTreeGenerator
+
+GAME = "/mnt/d/SteamLibrary/steamapps/common/Sand Playtest"
+BD = os.path.join(GAME, "Sand_Data/StreamingAssets/aa/StandaloneWindows64")
+META = os.path.join(GAME, "Sand_Data/il2cpp_data/Metadata/global-metadata.dat")
+DLL = os.path.join(GAME, "GameAssembly.dll")
+OUT = "/home/downloadpizza/sand_tools/extracted"
+UNITY = "6000.0.40f1"
+
+def build_generator():
+    g = TypeTreeGenerator(UNITY)
+    g.load_il2cpp(open(DLL, "rb").read(), open(META, "rb").read())
+    return g
+
+_node_cache = {}
+def nodes_for(gen, script):
+    key = (script.m_AssemblyName, script.m_Namespace, script.m_ClassName)
+    if key not in _node_cache:
+        full = (script.m_Namespace + "." if script.m_Namespace else "") + script.m_ClassName
+        try:
+            _node_cache[key] = gen.get_nodes(script.m_AssemblyName, full)
+        except Exception as e:
+            _node_cache[key] = None
+    return _node_cache[key]
+
+def load_env(*bundles):
+    paths = [os.path.join(BD, b) for b in bundles]
+    return UnityPy.load(*paths)
+
+def build_name_index(env):
+    """path_id -> m_Name for every object we can cheaply name (GameObjects, named MBs)."""
+    idx = {}
+    for o in env.objects:
+        try:
+            if o.type.name in ("GameObject",):
+                idx[o.path_id] = o.read().m_Name
+        except Exception:
+            pass
+    return idx
+
+def read_mb(gen, obj, name_idx=None):
+    """Read a MonoBehaviour into a plain dict; resolve PPtr dicts to {'->': name|pathid}."""
+    d = obj.read()
+    try:
+        script = d.m_Script.read()
+    except Exception:
+        return None
+    nodes = nodes_for(gen, script)
+    if not nodes:
+        return None
+    tree = obj.read_typetree(nodes)
+    return _clean(tree, name_idx, obj)
+
+def _clean(v, name_idx, obj):
+    if isinstance(v, dict):
+        # PPtr shape
+        if set(v.keys()) >= {"m_FileID", "m_PathID"} and len(v) <= 3:
+            pid = v["m_PathID"]
+            if pid == 0:
+                return None
+            nm = name_idx.get(pid) if name_idx else None
+            return {"ref": nm or pid}
+        return {k: _clean(x, name_idx, obj) for k, x in v.items()}
+    if isinstance(v, list):
+        return [_clean(x, name_idx, obj) for x in v]
+    return v
+
+if __name__ == "__main__":
+    print("building generator…", flush=True)
+    gen = build_generator()
+    print("generator ready", flush=True)
+    # quick validation on one loot table
+    env = load_env("lootsets_assets_all.bundle", "sand_monoscripts.bundle",
+                   "epb_assets_all.bundle", "configuration_assets_all.bundle")
+    name_idx = build_name_index(env)
+    print("name index:", len(name_idx), "entries", flush=True)
+    o = next(x for x in env.objects if x.type.name == "MonoBehaviour"
+             and x.read().m_Name == "POIShipMediumWeapons")
+    import pprint
+    pprint.pprint(read_mb(gen, o, name_idx))