nxconvert patched build

This fork fixes NSP conversion crashes caused by a divide-by-zero in progress calculation.

Changes:

• Initialize NSP progress total bytes before decrypting NCAs.
• Guard progress calculations against total_bytes == 0.
• Remember the keys path in an external nxconvert.ini next to the executable.
• Default the output directory to the selected input file's folder.
• Accept one command-line argument as the input file and prefill the GUI.

Example:

nxconvert.exe "H:\NS\Metal Dogs [0100A6E01681C000][v0][JP].nsp"

Default nxconvert.ini format:

[Settings]
keys=D:\Citron-Windows-Canary-Refresh_0.6.1\user11\keys\prod.keys