cli-parser-cleanup (#15)

Reviewed-on: moritz/ptouch-prnt#15

src/main.cpp

@@ -1,6 +1,6 @@
 /* 
     ptrnt - print labels on linux
-    Copyright (C) 2022-2023  Moritz Martinius
+    Copyright (C) 2022-2025  Moritz Martinius
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -22,7 +22,10 @@ int main(int argc, char** argv) {
     ptprnt::PtouchPrint ptouchprnt(PROJ_VERSION);
     int ret = ptouchprnt.init(argc, argv);
     if (ret != 0) {
-        return ret;
+        // Non-zero from init means don't continue
+        // Positive values = clean exit (help/version)
+        // Negative values = error
+        return ret > 0 ? 0 : ret;
     }
     return ptouchprnt.run();
 }