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>

dll/leakfix/stable/src.stable/logging.cpp

@@ -0,0 +1,74 @@
+#include "logging.h"
+#include <windows.h>
+#include <cstdio>
+#include <cstdarg>
+#include <cstring>
+
+namespace {
+HANDLE g_log = INVALID_HANDLE_VALUE;
+CRITICAL_SECTION g_cs;
+bool g_cs_inited = false;
+
+void ensure_cs() {
+    if (!g_cs_inited) {
+        InitializeCriticalSection(&g_cs);
+        g_cs_inited = true;
+    }
+}
+
+void write_line(const char* s, size_t len) {
+    if (g_log == INVALID_HANDLE_VALUE) return;
+    DWORD written = 0;
+    WriteFile(g_log, s, (DWORD)len, &written, nullptr);
+}
+}
+
+namespace leakfix {
+
+void log_init(const char* path) {
+    ensure_cs();
+    EnterCriticalSection(&g_cs);
+    if (g_log != INVALID_HANDLE_VALUE) { LeaveCriticalSection(&g_cs); return; }
+    g_log = CreateFileA(path, FILE_APPEND_DATA, FILE_SHARE_READ | FILE_SHARE_WRITE,
+                        nullptr, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
+    SetFilePointer(g_log, 0, nullptr, FILE_END);
+    LeaveCriticalSection(&g_cs);
+    logf("===== leakfix.dll loaded (pid=%lu) =====", GetCurrentProcessId());
+}
+
+void log_close() {
+    ensure_cs();
+    EnterCriticalSection(&g_cs);
+    if (g_log != INVALID_HANDLE_VALUE) {
+        CloseHandle(g_log);
+        g_log = INVALID_HANDLE_VALUE;
+    }
+    LeaveCriticalSection(&g_cs);
+}
+
+void logf(const char* fmt, ...) {
+    ensure_cs();
+    char buf[1024];
+    SYSTEMTIME st;
+    GetLocalTime(&st);
+    int n = std::snprintf(buf, sizeof(buf),
+        "[%04d-%02d-%02d %02d:%02d:%02d.%03d] ",
+        st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
+    va_list ap; va_start(ap, fmt);
+    int m = std::vsnprintf(buf + n, sizeof(buf) - n - 2, fmt, ap);
+    va_end(ap);
+    if (m < 0) m = 0;
+    int total = n + m;
+    if (total >= (int)sizeof(buf) - 1) total = sizeof(buf) - 2;
+    buf[total] = '\n';
+    buf[total + 1] = '\0';
+
+    EnterCriticalSection(&g_cs);
+    write_line(buf, (size_t)total + 1);
+    LeaveCriticalSection(&g_cs);
+
+    // Also forward to debugger if attached
+    OutputDebugStringA(buf);
+}
+
+} // namespace leakfix