Add signal crash handler and support automatic log backup

launch_miyoo.sh

@@ -2,6 +2,12 @@
 # Launcher CyberMatris per Miyoo Mini Plus (OnionOS / Stock OS)
 GAMEDIR=$(dirname "$0")
 LOGFILE="$GAMEDIR/cybermatris.log"
+
+# Preserva il log della sessione precedente (utile in caso di crash improvvisi)
+if [ -f "$LOGFILE" ]; then
+    mv "$LOGFILE" "$GAMEDIR/cybermatris.old.log"
+fi
+
 exec > "$LOGFILE" 2>&1
 set -x
 

main.cpp

@@ -1,4 +1,5 @@
 #include <SDL2/SDL.h>
+#include <csignal>
 #include <iostream>
 #include <chrono>
 #ifdef MIYOO_BUILD
@@ -12,7 +13,34 @@
 #include "Synth.hpp"
 #include "Renderer.hpp"
 
+// Crash signal handler to print diagnostic trace to cybermatris.log
+void crashHandler(int signum) {
+    std::cerr << "\n\n==================================================" << std::endl;
+    std::cerr << "[CRASH DETECTED] CyberMatris caught fatal signal " << signum;
+    switch (signum) {
+        case SIGSEGV: std::cerr << " (SIGSEGV: Segmentation Fault)"; break;
+        case SIGABRT: std::cerr << " (SIGABRT: Abort / Assertion failed)"; break;
+        case SIGFPE:  std::cerr << " (SIGFPE: Floating Point Exception)"; break;
+        case SIGILL:  std::cerr << " (SIGILL: Illegal Instruction)"; break;
+        case SIGBUS:  std::cerr << " (SIGBUS: Bus Error)"; break;
+        default:      std::cerr << " (Unknown Signal)"; break;
+    }
+    std::cerr << "\n==================================================" << std::endl;
+    std::cerr.flush();
+    
+    // Restore default handler and re-raise to complete execution termination
+    std::signal(signum, SIG_DFL);
+    std::raise(signum);
+}
+
 int main([[maybe_unused]] int argc, [[maybe_unused]] char* argv[]) {
+    // Register crash signal handlers
+    std::signal(SIGSEGV, crashHandler);
+    std::signal(SIGABRT, crashHandler);
+    std::signal(SIGFPE, crashHandler);
+    std::signal(SIGILL, crashHandler);
+    std::signal(SIGBUS, crashHandler);
+
     // 1. Initialize SDL2 subsystems
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) {
         std::cerr << "SDL could not initialize! SDL_Error: " << SDL_GetError() << std::endl;