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/identify_d3d_vtable.py

@@ -0,0 +1,63 @@
+"""identify_d3d_vtable.py <pid> <candidate_va>
+Read consecutive DWORDs from a candidate vtable address and report how
+many of them are valid d3d9.dll function pointers.
+IDirect3DDevice9 has 119 slots, IDirect3DTexture9 ~17, IDirect3D9 ~16.
+"""
+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)]
+
+D3D9_BASE = 0x6F4E0000
+D3D9_END  = 0x6F4E0000 + 0x17A000
+
+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])
+va = int(sys.argv[2], 0)
+
+h = k.OpenProcess(PROCESS_VM_READ | PROCESS_QUERY_INFORMATION, False, pid)
+if not h: print("OpenProcess fail"); sys.exit(2)
+
+data = rd(h, va, 4 * 130)
+if not data: print(f"unreadable at 0x{va:08x}"); sys.exit(3)
+
+# Count consecutive valid d3d9 function pointers
+slot_count = 0
+slots = []
+for i in range(130):
+    if i*4 + 4 > len(data): break
+    p = struct.unpack_from('<I', data, i*4)[0]
+    if D3D9_BASE <= p < D3D9_END:
+        slot_count = i + 1  # at least up to here, all valid
+        slots.append(p)
+    else:
+        # First non-d3d9 entry
+        slots.append(p)
+        if i > 3:
+            break
+
+print(f"Vtable @ 0x{va:08x}:  valid d3d9 slots = {slot_count}")
+print(f"  Slot 0:  0x{slots[0]:08x}")
+if slot_count > 2:  print(f"  Slot 2:  0x{slots[2]:08x}  (would be IUnknown::Release)")
+if slot_count > 16: print(f"  Slot 16: 0x{slots[16]:08x}  (could be IDirect3D9::CreateDevice if D3D9 vtable, or IDirect3DDevice9::Reset)")
+if slot_count > 23: print(f"  Slot 23: 0x{slots[23]:08x}  (would be IDirect3DDevice9::CreateTexture)")
+if slot_count > 28: print(f"  Slot 28: 0x{slots[28]:08x}  (would be IDirect3DDevice9::CreateRenderTarget)")
+
+# Identify
+if slot_count >= 119:
+    print(f"\n*** LIKELY IDirect3DDevice9 (119 slots expected) ***")
+elif 14 <= slot_count <= 20:
+    print(f"\nLIKELY IDirect3D9 or IDirect3DTexture9 (small)")
+elif 4 <= slot_count <= 10:
+    print(f"\nLIKELY IUnknown derivative (very small)")
+else:
+    print(f"\nUnknown — {slot_count} slots")
+
+k.CloseHandle(h)