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/patch_palette_v3b.py

@@ -0,0 +1,89 @@
+"""patch_palette_v3b.py <pid> [--revert]
+
+v3b: extended v3 — patches BOTH makeModifiedPalette overloads.
+
+  Site 1 (no-arg overload, FUN_0053efe0):
+    addr 0x0053effe  ff 40 24  -> 90 90 90    ; nop refcount++
+
+  Site 2 (2-arg overload, FUN_0053f120):
+    addr 0x0053f19c  ff 46 24  -> 90 90 90    ; nop refcount++
+
+Both write a refcount++ on a freshly-constructed (refcount=1) palette,
+leaving it at refcount=2 — which is one short of being released back to
+zero by the typical cleanup chain (releasePalette + CSurface dtor).
+"""
+import ctypes, ctypes.wintypes as wt, sys
+
+SITES = [
+    (0x0053effe, bytes([0xff, 0x40, 0x24]), bytes([0x90, 0x90, 0x90])),
+    (0x0053f19c, bytes([0xff, 0x46, 0x24]), bytes([0x90, 0x90, 0x90])),
+]
+
+PROCESS_VM_READ           = 0x0010
+PROCESS_VM_WRITE          = 0x0020
+PROCESS_VM_OPERATION      = 0x0008
+PROCESS_QUERY_INFORMATION = 0x0400
+PAGE_EXECUTE_READWRITE    = 0x40
+
+k32 = ctypes.windll.kernel32
+OpenProcess        = k32.OpenProcess
+OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]; OpenProcess.restype = wt.HANDLE
+CloseHandle        = k32.CloseHandle
+CloseHandle.argtypes = [wt.HANDLE]; CloseHandle.restype = wt.BOOL
+ReadProcessMemory  = k32.ReadProcessMemory
+ReadProcessMemory.argtypes = [wt.HANDLE, wt.LPCVOID, wt.LPVOID, ctypes.c_size_t,
+                              ctypes.POINTER(ctypes.c_size_t)]
+ReadProcessMemory.restype = wt.BOOL
+WriteProcessMemory = k32.WriteProcessMemory
+WriteProcessMemory.argtypes = [wt.HANDLE, wt.LPVOID, wt.LPCVOID, ctypes.c_size_t,
+                               ctypes.POINTER(ctypes.c_size_t)]
+WriteProcessMemory.restype = wt.BOOL
+VirtualProtectEx   = k32.VirtualProtectEx
+VirtualProtectEx.argtypes = [wt.HANDLE, wt.LPVOID, ctypes.c_size_t,
+                             wt.DWORD, ctypes.POINTER(wt.DWORD)]
+VirtualProtectEx.restype = wt.BOOL
+
+
+def patch_site(h, addr, orig, patched, revert):
+    cur = (ctypes.c_ubyte * 3)(); sz = ctypes.c_size_t(0)
+    if not ReadProcessMemory(h, addr, cur, 3, ctypes.byref(sz)):
+        print(f"  read failed @ 0x{addr:08x}: err={ctypes.get_last_error()}"); return False
+    cur_b = bytes(cur)
+    target = orig if revert else patched
+    expect_before = patched if revert else orig
+    print(f"  @ 0x{addr:08x}: cur={' '.join(f'{b:02x}' for b in cur_b)}", end="")
+    if cur_b == target:
+        print(f"  already {'reverted' if revert else 'patched'}")
+        return True
+    if cur_b != expect_before:
+        print(f"  UNEXPECTED (wanted {' '.join(f'{b:02x}' for b in expect_before)}) — skip")
+        return False
+    old_prot = wt.DWORD(0)
+    if not VirtualProtectEx(h, addr, 3, PAGE_EXECUTE_READWRITE, ctypes.byref(old_prot)):
+        print(f"  VirtualProtectEx failed: err={ctypes.get_last_error()}"); return False
+    new = (ctypes.c_ubyte * 3)(*target)
+    if not WriteProcessMemory(h, addr, new, 3, ctypes.byref(sz)):
+        print(f"  write failed: err={ctypes.get_last_error()}"); return False
+    restored = wt.DWORD(0)
+    VirtualProtectEx(h, addr, 3, old_prot.value, ctypes.byref(restored))
+    print(f"  -> {' '.join(f'{b:02x}' for b in target)}  ({'reverted' if revert else 'patched'})")
+    return True
+
+
+def main():
+    pid    = int(sys.argv[1])
+    revert = "--revert" in sys.argv
+
+    h = OpenProcess(PROCESS_VM_READ|PROCESS_VM_WRITE|PROCESS_VM_OPERATION|PROCESS_QUERY_INFORMATION,
+                    False, pid)
+    if not h:
+        print(f"OpenProcess({pid}) failed: err={ctypes.get_last_error()}"); sys.exit(2)
+
+    print(f"PID {pid}:")
+    for addr, orig, patched in SITES:
+        patch_site(h, addr, orig, patched, revert)
+    CloseHandle(h)
+
+
+if __name__ == "__main__":
+    main()