Auto-attack: bow shots chain at full speed, arts start by their cooldown; hang watchdog

- The shot end's button check (0x4def52) answers "held" for the auto-attack
  target, like the melee swing end.
- An art order counts as started when the art's cooldown rises, so bow arts
  and arts ordered mid-swing hand over to auto-attack.
- re/crash.cpp: a watchdog writes sacred_re_hang.dmp when the engine tick
  stops for 10 s while the game is in front.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/re/crash.cpp

@@ -3,6 +3,11 @@
 // and sacred_re_crash.dmp next to the DLL. The game may install its own
 // filter later; SetUnhandledExceptionFilter is hooked so ours stays first and
 // passes the crash on to the game's afterwards.
+//
+// Hangs: a watchdog thread writes sacred_re_hang.dmp (all threads) when the
+// engine tick (re::EngineHeartbeat) has stopped for kHangMs while the game
+// window is in front; once per hang. The game freezing on F2 while walking
+// (2026-10-18) left no report.
 
 #include "re/crash.h"
 
@@ -105,6 +110,45 @@ void WriteReport(EXCEPTION_POINTERS* info) {
     }
 }
 
+constexpr DWORD kHangMs = 10000;
+volatile LONG g_lastBeat = 0;  // GetTickCount of the last engine tick, 0: no game running
+
+bool GameInFront() {
+    DWORD process = 0;
+    GetWindowThreadProcessId(GetForegroundWindow(), &process);
+    return process == GetCurrentProcessId();
+}
+
+void WriteHangDump() {
+    HANDLE dump = CreateFileW((g_dir + L"sacred_re_hang.dmp").c_str(), GENERIC_WRITE, 0, nullptr, CREATE_ALWAYS,
+                              FILE_ATTRIBUTE_NORMAL, nullptr);
+    if (dump != INVALID_HANDLE_VALUE) {
+        MiniDumpWriteDump(GetCurrentProcess(), GetCurrentProcessId(), dump,
+                          static_cast<MINIDUMP_TYPE>(MiniDumpWithIndirectlyReferencedMemory | MiniDumpWithThreadInfo),
+                          nullptr, nullptr, nullptr);
+        CloseHandle(dump);
+    }
+}
+
+DWORD WINAPI Watchdog(void*) {
+    bool reported = false;
+    for (;;) {
+        Sleep(1000);
+        const DWORD beat = static_cast<DWORD>(g_lastBeat);
+        // Signed: a tick may land between reading the beat and the clock.
+        if (beat == 0 || static_cast<LONG>(GetTickCount() - beat) < static_cast<LONG>(kHangMs)) {
+            reported = false;
+            continue;
+        }
+        if (!reported && GameInFront()) {
+            reported = true;
+            Log("hang: no engine tick for %lu ms, writing sacred_re_hang.dmp", GetTickCount() - beat);
+            WriteHangDump();
+            Log("hang: dump written");
+        }
+    }
+}
+
 LONG WINAPI Filter(EXCEPTION_POINTERS* info) {
     if (InterlockedExchange(&g_reported, 1) == 0) {
         WriteReport(info);
@@ -117,6 +161,13 @@ LONG WINAPI Filter(EXCEPTION_POINTERS* info) {
 void InstallCrashHandler(const std::wstring& dir) {
     g_dir = dir;
     g_gameFilter = SetUnhandledExceptionFilter(&Filter);
+    if (HANDLE thread = CreateThread(nullptr, 0, &Watchdog, nullptr, 0, nullptr)) {
+        CloseHandle(thread);
+    }
+}
+
+void EngineHeartbeat(bool running) {
+    InterlockedExchange(&g_lastBeat, running ? static_cast<LONG>(GetTickCount() | 1) : 0);
 }
 
 } // namespace re