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/dump_260k_content.py

@@ -0,0 +1,73 @@
+"""dump_260k_content.py <pid>
+For a few 260KB regions, dump first 128 bytes + mid + tail to characterize
+whether they're zeroed (free pool), structured (live d3d9 surface), or
+texture data."""
+import ctypes, ctypes.wintypes as wt, sys, struct
+
+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])
+h = k.OpenProcess(0x410, False, pid)
+if not h: print("OpenProcess fail"); sys.exit(2)
+
+# Find 260KB regions
+candidates = []
+mbi = MBI(); addr = 0
+while k.VirtualQueryEx(h, addr, ctypes.byref(mbi), ctypes.sizeof(mbi)):
+    base = mbi.BaseAddress or 0
+    if mbi.State == 0x1000 and mbi.RegionSize == 266240 and (mbi.Type & 0x20000):
+        candidates.append(base)
+    next_addr = base + mbi.RegionSize
+    if next_addr <= addr: break
+    addr = next_addr
+    if addr >= 0x80000000: break
+
+print(f"260KB regions: {len(candidates)}")
+
+# Histogram of first DWORD across ALL of them
+from collections import Counter
+first_dwords = []
+for b in candidates:
+    d = rd(h, b, 4)
+    if d: first_dwords.append(struct.unpack('<I', d)[0])
+c = Counter(first_dwords)
+print("Top first-DWORD values (offset 0):")
+for v, n in c.most_common(8):
+    print(f"  0x{v:08x}: {n} ({n*100/len(first_dwords):.1f}%)")
+
+# Sample a few in detail
+import random
+random.seed(42)
+sample_count = 4
+sample = random.sample(candidates, sample_count)
+for b in sample:
+    print(f"\n=== Region @0x{b:08x} (260KB) ===")
+    for off, label in [(0, "first 64B"), (256, "+0x100"),
+                       (4096, "+0x1000 (start of pixel data?)"),
+                       (133120, "midpoint"),
+                       (262144, "+0x40000 (256KB mark)"),
+                       (266112, "last 128 bytes")]:
+        d = rd(h, b + off, 64 if 'first' in label or 'last' not in label else 128)
+        if not d: continue
+        # Count zero bytes
+        zeros = d.count(0)
+        non_zero = len(d) - zeros
+        print(f"  +0x{off:06x} ({label}, {zeros}/{len(d)} zero): "
+              f"{d[:32].hex(' ')}{'...' if len(d)>32 else ''}")
+
+k.CloseHandle(h)