tools: SAND .wbt + game-data extraction scripts

Python tooling for decoding walker saves and mining game data:
sand.py / build_wbt.py / walker_hashes.py / harvest_hashes.py (.wbt
codec + hashes), extract_*/loot_probe/odin_read/unitybundle (asset
parsing), make_*_wiki + render_wiki (wiki generation), recover_key.
Paths point at the local extracted/, wiki/, and Walkers symlink.

harvest_hashes.py

@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+"""Harvest per-part hashes from SAND walker saves (100% offline, no injection/proxy).
+
+Every compartment placed in the in-game editor writes its DefinitionHash (and
+CompartmentHash) into the .wbt save. This scans all saves, decodes them, and
+merges every (EpbId -> {DefinitionHash, CompartmentHash}) into a JSON table,
+deduping and keeping a history of any older hash values seen per part.
+
+Re-run it any time after building/saving new walkers to grow the table.
+
+Usage:
+  harvest_hashes.py            # scan the live Walkers dir + snapshots, update table
+  harvest_hashes.py <dir> ...  # scan extra dirs of .wbt too
+"""
+import sys, gzip, json, glob, os, hashlib
+
+KEY = bytes.fromhex('70dd1f2a0b4a'); CHUNK = 0xA000
+WBT_DIR = '/home/downloadpizza/sand_tools/Walkers'   # symlink -> live game saves (*.wbt)
+EXTRACTED = '/home/downloadpizza/sand_tools/extracted'
+OUT = os.path.join(EXTRACTED, 'definition_hashes_known.json')
+COMPDB = os.path.join(EXTRACTED, 'CompartmentsDatabase.json')
+
+try:
+    from bson import decode
+except ImportError:
+    sys.exit("need pymongo: ~/sand_tools/venv/bin/pip install pymongo")
+
+def decode_wbt(path):
+    raw = gzip.decompress(open(path, 'rb').read())
+    dec = bytes(raw[i] ^ KEY[(i % CHUNK) % 6] for i in range(len(raw)))
+    return decode(dec)
+
+def main():
+    dirs = [WBT_DIR, os.path.join(os.path.expanduser('~'), 'sand_tools', 'snapshots')] + sys.argv[1:]
+    files = []
+    for d in dirs:
+        files += glob.glob(os.path.join(d, '*.wbt'))
+    # snapshots are decoded already (.dec) -> handle separately
+    dec_files = []
+    for d in dirs:
+        dec_files += glob.glob(os.path.join(d, '*.dec'))
+
+    # rebuild fresh from saves+snapshots (the authoritative source); snapshots persist
+    # history even if live .wbt files are later deleted.
+    table = {}
+
+    def note(epb, comp, deff):
+        e = table.setdefault(epb, {'DefinitionHash': None, 'DefinitionHash_history': [],
+                                   'CompartmentHash': None, 'CompartmentHash_history': []})
+        for field, hist, val in [('DefinitionHash', 'DefinitionHash_history', deff),
+                                 ('CompartmentHash', 'CompartmentHash_history', comp)]:
+            if not val:
+                continue
+            if e[field] and e[field] != val and e[field] not in e[hist]:
+                e[hist].append(e[field])
+            e[field] = val
+
+    scanned = 0
+    def walkers_from(doc):
+        w = doc['walker']
+        return [w['Chassis']] + w['Compartments']
+
+    for f in sorted(set(files)):
+        try:
+            doc = decode_wbt(f); scanned += 1
+        except Exception as ex:
+            print(f"skip {os.path.basename(f)}: {ex}"); continue
+        for c in walkers_from(doc):
+            note(c['EpbId'], c.get('CompartmentHash'), c.get('DefinitionHash'))
+    for f in sorted(set(dec_files)):
+        try:
+            doc = decode(open(f, 'rb').read()); scanned += 1
+        except Exception:
+            continue
+        try:
+            for c in walkers_from(doc):
+                note(c['EpbId'], c.get('CompartmentHash'), c.get('DefinitionHash'))
+        except Exception:
+            pass
+
+    # cross-check CompartmentHash against CompartmentsDatabase (authoritative current value)
+    total_parts = None
+    if os.path.exists(COMPDB):
+        db = json.load(open(COMPDB))
+        total_parts = len(db['compartments'])
+        calc = {c['entityId']: hashlib.md5(json.dumps(c, separators=(',', ':')).encode()).hexdigest().upper()
+                for c in db['compartments']}
+        for epb, e in table.items():
+            if epb in calc:
+                e['CompartmentHash_computed'] = calc[epb]
+
+    out = {
+        '_note': ("Per-part hashes harvested from walker saves. CompartmentHash is also computed "
+                  "offline from CompartmentsDatabase (CompartmentHash_computed, authoritative). "
+                  "DefinitionHash is server-sourced and only known for parts that appear in a save — "
+                  "build a part in-game and re-run this to capture it."),
+        'definition_known': sum(1 for e in table.values() if e.get('DefinitionHash')),
+        'total_parts_in_db': total_parts,
+        'parts': dict(sorted(table.items())),
+    }
+    os.makedirs(os.path.dirname(OUT), exist_ok=True)
+    json.dump(out, open(OUT, 'w'), indent=2)
+    print(f"scanned {scanned} saves; {out['definition_known']} parts with DefinitionHash"
+          + (f" / {total_parts} total" if total_parts else "") + f"\nwrote {OUT}")
+
+if __name__ == '__main__':
+    main()