Add option to start Thunderbird on minimized system startup

[francs97]

I would like an option to be able to start #Thunderbird at system startup already minimized or a mode that sends notifications even if the program is closed (kind of like Windows Mail does

[shunf4]

I've half-vibe-coded a tool that injects, hooks (ShowWindow()) and starts Thunderbird Mail x64 for Windows in minimized mode.

https://github.com/shunf4/tb_win_min_launch