Add Windows build support via MSYS2 and fix platform-specific code

Guard X11 display crash handler with __linux__, add Windows GlobalMemoryStatusEx
path in memory_monitor, guard warden cache paths with APPDATA on Windows, and
make pkg-config optional in CMakeLists with a find_library fallback. Add Windows
x86-64 CI job using MSYS2 MINGW64 to the build workflow.

src/core/memory_monitor.cpp

@@ -3,11 +3,16 @@
 #include <fstream>
 #include <string>
 #include <sstream>
+#ifdef _WIN32
+#include <windows.h>
+#else
 #include <sys/sysinfo.h>
+#endif
 
 namespace wowee {
 namespace core {
 
+#ifndef _WIN32
 namespace {
 size_t readMemAvailableBytesFromProc() {
     std::ifstream meminfo("/proc/meminfo");
@@ -26,6 +31,7 @@ size_t readMemAvailableBytesFromProc() {
     return 0;
 }
 } // namespace
+#endif
 
 MemoryMonitor& MemoryMonitor::getInstance() {
     static MemoryMonitor instance;
@@ -33,6 +39,16 @@ MemoryMonitor& MemoryMonitor::getInstance() {
 }
 
 void MemoryMonitor::initialize() {
+#ifdef _WIN32
+    ULONGLONG totalKB = 0;
+    if (GetPhysicallyInstalledSystemMemory(&totalKB)) {
+        totalRAM_ = static_cast<size_t>(totalKB) * 1024ull;
+        LOG_INFO("System RAM detected: ", totalRAM_ / (1024 * 1024 * 1024), " GB");
+    } else {
+        totalRAM_ = 16ull * 1024 * 1024 * 1024;
+        LOG_WARNING("Could not detect system RAM, assuming 16GB");
+    }
+#else
     struct sysinfo info;
     if (sysinfo(&info) == 0) {
         totalRAM_ = static_cast<size_t>(info.totalram) * info.mem_unit;
@@ -42,9 +58,18 @@ void MemoryMonitor::initialize() {
         totalRAM_ = 16ull * 1024 * 1024 * 1024;
         LOG_WARNING("Could not detect system RAM, assuming 16GB");
     }
+#endif
 }
 
 size_t MemoryMonitor::getAvailableRAM() const {
+#ifdef _WIN32
+    MEMORYSTATUSEX status;
+    status.dwLength = sizeof(status);
+    if (GlobalMemoryStatusEx(&status)) {
+        return static_cast<size_t>(status.ullAvailPhys);
+    }
+    return totalRAM_ / 2;
+#else
     // Best source on Linux for reclaimable memory headroom.
     if (size_t memAvailable = readMemAvailableBytesFromProc(); memAvailable > 0) {
         return memAvailable;
@@ -59,6 +84,7 @@ size_t MemoryMonitor::getAvailableRAM() const {
         return (totalRAM_ > 0 && available > totalRAM_) ? totalRAM_ : available;
     }
     return totalRAM_ / 2;  // Fallback: assume 50% available
+#endif
 }
 
 size_t MemoryMonitor::getRecommendedCacheBudget() const {

src/game/game_handler.cpp

@@ -2397,11 +2397,15 @@ bool GameHandler::loadWardenCRFile(const std::string& moduleHashHex) {
     wardenCREntries_.clear();
 
     // Look for .cr file in warden cache
-    std::string homeDir;
-    if (const char* h = std::getenv("HOME")) homeDir = h;
-    else homeDir = ".";
-
-    std::string crPath = homeDir + "/.local/share/wowee/warden_cache/" + moduleHashHex + ".cr";
+    std::string cacheBase;
+#ifdef _WIN32
+    if (const char* h = std::getenv("APPDATA")) cacheBase = std::string(h) + "\\wowee\\warden_cache";
+    else cacheBase = ".\\warden_cache";
+#else
+    if (const char* h = std::getenv("HOME")) cacheBase = std::string(h) + "/.local/share/wowee/warden_cache";
+    else cacheBase = "./warden_cache";
+#endif
+    std::string crPath = cacheBase + "/" + moduleHashHex + ".cr";
 
     std::ifstream crFile(crPath, std::ios::binary);
     if (!crFile) {
@@ -2581,10 +2585,15 @@ void GameHandler::handleWardenData(network::Packet& packet) {
 
                 // Cache raw module to disk
                 {
-                    std::string homeDir;
-                    if (const char* h = std::getenv("HOME")) homeDir = h;
-                    else homeDir = ".";
-                    std::string cacheDir = homeDir + "/.local/share/wowee/warden_cache";
+#ifdef _WIN32
+                    std::string cacheDir;
+                    if (const char* h = std::getenv("APPDATA")) cacheDir = std::string(h) + "\\wowee\\warden_cache";
+                    else cacheDir = ".\\warden_cache";
+#else
+                    std::string cacheDir;
+                    if (const char* h = std::getenv("HOME")) cacheDir = std::string(h) + "/.local/share/wowee/warden_cache";
+                    else cacheDir = "./warden_cache";
+#endif
                     std::filesystem::create_directories(cacheDir);
 
                     std::string hashHex;

src/game/warden_module.cpp

@@ -906,13 +906,18 @@ bool WardenModule::initializeModule() {
 // ============================================================================
 
 WardenModuleManager::WardenModuleManager() {
-    // Set cache directory: ~/.local/share/wowee/warden_cache/
-    const char* home = std::getenv("HOME");
-    if (home) {
+    // Set cache directory
+#ifdef _WIN32
+    if (const char* appdata = std::getenv("APPDATA"))
+        cacheDirectory_ = std::string(appdata) + "\\wowee\\warden_cache";
+    else
+        cacheDirectory_ = ".\\warden_cache";
+#else
+    if (const char* home = std::getenv("HOME"))
         cacheDirectory_ = std::string(home) + "/.local/share/wowee/warden_cache";
-    } else {
+    else
         cacheDirectory_ = "./warden_cache";
-    }
+#endif
 
     // Create cache directory if it doesn't exist
     std::filesystem::create_directories(cacheDirectory_);

src/main.cpp

@@ -3,6 +3,7 @@
 #include <exception>
 #include <csignal>
 #include <SDL2/SDL.h>
+#ifdef __linux__
 #include <X11/Xlib.h>
 
 // Keep a persistent X11 connection for emergency mouse release in signal handlers.
@@ -16,6 +17,9 @@ static void releaseMouseGrab() {
         XFlush(g_emergencyDisplay);
     }
 }
+#else
+static void releaseMouseGrab() {}
+#endif
 
 static void crashHandler(int sig) {
     releaseMouseGrab();
@@ -24,7 +28,9 @@ static void crashHandler(int sig) {
 }
 
 int main([[maybe_unused]] int argc, [[maybe_unused]] char* argv[]) {
+#ifdef __linux__
     g_emergencyDisplay = XOpenDisplay(nullptr);
+#endif
     std::signal(SIGSEGV, crashHandler);
     std::signal(SIGABRT, crashHandler);
     std::signal(SIGFPE,  crashHandler);
@@ -46,7 +52,9 @@ int main([[maybe_unused]] int argc, [[maybe_unused]] char* argv[]) {
         app.shutdown();
 
         LOG_INFO("Application exited successfully");
+#ifdef __linux__
         if (g_emergencyDisplay) { XCloseDisplay(g_emergencyDisplay); g_emergencyDisplay = nullptr; }
+#endif
         return 0;
     }
     catch (const std::exception& e) {