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/find_holder.py

@@ -0,0 +1,63 @@
+"""find_holder.py <pid> <target_va>
+Scan all committed private RW memory in process for pointers equal to target_va.
+Reports addresses where the pointer was found + small context."""
+import ctypes, ctypes.wintypes as wt, sys, struct
+
+PROCESS_VM_READ = 0x10
+PROCESS_QUERY_INFORMATION = 0x400
+k = ctypes.windll.kernel32
+k.OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]; k.OpenProcess.restype = wt.HANDLE
+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, wt.LPCVOID, ctypes.c_void_p, ctypes.c_size_t]
+k.VirtualQueryEx.restype = ctypes.c_size_t
+
+class MBI(ctypes.Structure):
+    _fields_ = [("BaseAddress", ctypes.c_void_p), ("AllocationBase", ctypes.c_void_p),
+                ("AllocationProtect", wt.DWORD), ("RegionSize", ctypes.c_size_t),
+                ("State", wt.DWORD), ("Protect", wt.DWORD), ("Type", wt.DWORD)]
+
+def rd(h, va, n):
+    buf = (ctypes.c_ubyte * n)(); sz = ctypes.c_size_t(0)
+    if not k.ReadProcessMemory(h, va, buf, n, ctypes.byref(sz)): return None
+    return bytes(buf[:sz.value])
+
+pid = int(sys.argv[1])
+target = int(sys.argv[2], 0)
+target_bytes = struct.pack('<I', target)
+
+h = k.OpenProcess(PROCESS_VM_READ | PROCESS_QUERY_INFORMATION, False, pid)
+if not h: print("OpenProcess fail"); sys.exit(2)
+
+found = []
+mbi = MBI()
+addr = 0
+while k.VirtualQueryEx(h, addr, ctypes.byref(mbi), ctypes.sizeof(mbi)):
+    base = mbi.BaseAddress or 0
+    sz = mbi.RegionSize
+    if (mbi.State == 0x1000 and mbi.Type == 0x20000 and (mbi.Protect & 0xFF) in (0x04, 0x40)
+        and sz < 64*1024*1024):
+        data = rd(h, base, sz)
+        if data:
+            off = 0
+            while True:
+                off = data.find(target_bytes, off)
+                if off < 0: break
+                if (off & 3) == 0:
+                    holder_va = base + off
+                    # Read 32 bytes around to see what context
+                    ctx = data[max(0, off-16): off+16].hex(' ')
+                    found.append((holder_va, ctx))
+                    if len(found) >= 20: break
+                off += 4
+        if len(found) >= 20: break
+    next_addr = base + sz
+    if next_addr <= addr: break
+    addr = next_addr
+    if addr >= 0x80000000: break
+
+k.CloseHandle(h)
+
+print(f"Pointers to 0x{target:08x} (top {len(found)}):")
+for holder_va, ctx in found:
+    print(f"  @0x{holder_va:08x}: ...{ctx}...")