Add and expose sanitizing logic

lib/Logging/Logging.cpp

@@ -80,6 +80,12 @@ std::string getLastLogs() {
   return output;
 }
 
+void sanitizeLogHead() {
+  if (logHead >= MAX_LOG_LINES) {
+    logHead = 0;
+  }
+}
+
 void clearLastLogs() {
   for (size_t i = 0; i < MAX_LOG_LINES; i++) {
     logMessages[i][0] = '\0';

lib/Logging/Logging.h

@@ -57,6 +57,9 @@ void logPrintf(const char* level, const char* origin, const char* format, ...);
 
 std::string getLastLogs();
 void clearLastLogs();
+// Clamps logHead into range without wiping messages — safe to call on panic
+// reboots where the panic occurred before begin() ever had a chance to run.
+void sanitizeLogHead();
 
 class MySerialImpl : public Print {
  public:

lib/hal/HalSystem.cpp

@@ -76,6 +76,10 @@ void begin() {
   // `clearPanic()` to clear it after dumping
   if (!isRebootFromPanic()) {
     clearPanic();
+  } else {
+    // Panic reboot: preserve logs and panic info, but clamp logHead in case the
+    // panic occurred before begin() ever ran (e.g. in a static constructor).
+    sanitizeLogHead();
   }
 }