卫戍协议：盟约 web remake — initial import

Online co-op browser remake of Arknights' Stronghold Protocol: Alliance
(client-simulated combat, official waves/bonds/items/strategies, 3D board,
facing wheel, operator loadout, official emotes, deployment scripts).

tools/local-extract/aklz4.py

@@ -0,0 +1,30 @@
+# LZ4AK decompressor for Arknights bundles (algorithm from isHarryh/Ark-Unpacker, BSD-3, via MooncellWiki/UnityPy)
+import lz4.block
+from UnityPy.helpers import CompressionHelper
+from UnityPy.enums.BundleFile import CompressionFlags
+
+def _xlen(d, p, m):
+    l = 0
+    while p < m:
+        b = d[p]; l += b; p += 1
+        if b != 0xFF: break
+    return l, p
+
+def decompress_lz4ak(data, usize):
+    ip = op = 0
+    d = bytearray(data); n = len(d)
+    while ip < n:
+        lit = d[ip] & 0xF; mat = (d[ip] >> 4) & 0xF
+        d[ip] = (lit << 4) | mat; ip += 1
+        if lit == 0xF:
+            l, ip = _xlen(d, ip, n); lit += l
+        ip += lit; op += lit
+        if op >= usize: break
+        off = (d[ip] << 8) | d[ip + 1]
+        d[ip] = off & 0xFF; d[ip + 1] = (off >> 8) & 0xFF; ip += 2
+        if mat == 0xF:
+            l, ip = _xlen(d, ip, n); mat += l
+        op += mat + 4
+    return lz4.block.decompress(bytes(d), usize)
+
+CompressionHelper.DECOMPRESSION_MAP[CompressionFlags.LZHAM] = decompress_lz4ak