Add magic value

lib/Logging/Logging.h

@@ -57,10 +57,10 @@ void logPrintf(const char* level, const char* origin, const char* format, ...);
 
 std::string getLastLogs();
 void clearLastLogs();
-// Clamps logHead into range. Returns true if logHead was out of range (repaired),
-// which also means logMessages is untrusted garbage. Callers should call
-// clearLastLogs() when this returns true so getLastLogs() does not dump corrupt
-// data into crash reports.
+// Validates the RTC log state (magic word + logHead range). Returns true if
+// corruption was detected (magic mismatch or logHead out of range), meaning
+// logMessages is untrusted garbage. Callers should call clearLastLogs() when
+// this returns true so getLastLogs() does not dump corrupt data into crash reports.
 bool sanitizeLogHead();
 
 class MySerialImpl : public Print {