Initial commit — leak-hunt project complete

Five bugs identified and patched in retail Asheron's Call client:
- v3b: palette refcount over-increment (3-byte NOP at two sites)
- v5: RenderSurface PurgeResource no-op stub (vtable slot 2 thunk)
- v11: two dangling-pointer crash guards (NULL-check + reorder)
- v14: CEnvCell::Destroy ClipPlaneList leak (18-byte JMP to cleanup thunk)
- v22: unpacker stale-pointer SEH guard (whole-function __try/__except)

All five ship in leakfix.dll (117 KB, SHA d282f23c…) which is loaded
by acclient.exe at process start via PE import table patching by
tools/install_leakfix.py.

Controlled 15-client fleet soak: unpatched control died at 26h with
palette exhaustion; all 14 patched clients survived past that point
and reached ≥5-day uptime.

Residual ~15 MB/h growth traced to d3d9.dll's internal slab allocator
(260KB surface backing buffers retained after Release). See REPORT.md
§10 for the full investigation; conclusion is that it's unfixable from
outside d3d9.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/position_sample_dump.py

@@ -0,0 +1,100 @@
+"""position_sample_dump.py <pid> [count=10]
+
+For a few Position hits, print the surrounding bytes raw so we can
+visually inspect the layout. Goal: see if there's a heap-block
+header pattern we missed.
+"""
+import ctypes
+import ctypes.wintypes as wt
+import struct
+import sys
+
+POSITION_VT = 0x00797910
+
+PROCESS_VM_READ = 0x10
+PROCESS_QUERY_INFORMATION = 0x400
+
+
+class MBI(ctypes.Structure):
+    _fields_ = [('BaseAddress', ctypes.c_void_p),
+                ('AllocationBase', ctypes.c_void_p),
+                ('AllocationProtect', wt.DWORD),
+                ('PartitionId', wt.WORD),
+                ('RegionSize', ctypes.c_size_t),
+                ('State', wt.DWORD),
+                ('Protect', wt.DWORD),
+                ('Type', wt.DWORD)]
+
+
+k = ctypes.windll.kernel32
+k.OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]; k.OpenProcess.restype = wt.HANDLE
+k.CloseHandle.argtypes = [wt.HANDLE]; k.CloseHandle.restype = wt.BOOL
+k.ReadProcessMemory.argtypes = [wt.HANDLE, wt.LPCVOID, wt.LPVOID, ctypes.c_size_t,
+                                ctypes.POINTER(ctypes.c_size_t)]
+k.ReadProcessMemory.restype = wt.BOOL
+k.VirtualQueryEx.argtypes = [wt.HANDLE, ctypes.c_void_p, ctypes.POINTER(MBI), ctypes.c_size_t]
+k.VirtualQueryEx.restype = ctypes.c_size_t
+
+
+def hexdump(addr, data, prefix=""):
+    for i in range(0, len(data), 16):
+        chunk = data[i:i+16]
+        h = " ".join(f"{b:02x}" for b in chunk)
+        a = "".join(chr(b) if 32 <= b < 127 else '.' for b in chunk)
+        dws = " ".join(f"{struct.unpack_from('<I', chunk, j)[0]:08x}"
+                       for j in range(0, min(16, len(chunk) - (len(chunk) % 4)), 4))
+        print(f"{prefix}0x{addr+i:08x}: {h:<47}  | {dws}  | {a}")
+
+
+def main():
+    pid = int(sys.argv[1])
+    want = int(sys.argv[2]) if len(sys.argv) > 2 else 10
+
+    h = k.OpenProcess(PROCESS_VM_READ | PROCESS_QUERY_INFORMATION, False, pid)
+    if not h:
+        print(f"OpenProcess err={ctypes.get_last_error()}"); return 1
+
+    shown = 0
+    mbi = MBI()
+    addr = 0
+    while k.VirtualQueryEx(h, addr, ctypes.byref(mbi), ctypes.sizeof(mbi)) and shown < want:
+        pr = mbi.Protect & 0xff
+        if (mbi.State == 0x1000 and mbi.Type == 0x20000
+                and pr in (0x04, 0x40)):
+            buf = (ctypes.c_ubyte * mbi.RegionSize)()
+            sz = ctypes.c_size_t(0)
+            if k.ReadProcessMemory(h, mbi.BaseAddress, buf,
+                                   mbi.RegionSize, ctypes.byref(sz)):
+                data = bytes(buf[:sz.value])
+                end = (len(data) // 4) * 4
+                # find positions in this region
+                pos_offs = []
+                for off in range(0, end, 4):
+                    if struct.unpack_from("<I", data, off)[0] == POSITION_VT:
+                        pos_offs.append(off)
+                # sample first few
+                for off in pos_offs[:3]:
+                    if shown >= want:
+                        break
+                    shown += 1
+                    va_pos = mbi.BaseAddress + off
+                    region_kb = mbi.RegionSize // 1024
+                    print(f"\n=== Position #{shown} @ VA 0x{va_pos:08x} "
+                          f"(region 0x{mbi.BaseAddress:08x} {region_kb}KB, "
+                          f"in-region offset 0x{off:x}, "
+                          f"positions-in-region={len(pos_offs)}) ===")
+                    # dump 64 bytes BEFORE position vt
+                    lo = max(0, off - 64)
+                    hexdump(mbi.BaseAddress + lo, data[lo:off], prefix="  before  ")
+                    print("  POSITION:")
+                    hexdump(mbi.BaseAddress + off, data[off:off + 128], prefix="  pos+ctx ")
+        addr = (mbi.BaseAddress or 0) + mbi.RegionSize
+        if addr >= 0x80000000 or shown >= want:
+            break
+
+    k.CloseHandle(h)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())