[BUG] Process keeps running when closing Choose Initial Fleet screen

Summary:
When closing the Select Fleet screen at New Game start, the window closes but the process continues to run. The game will not restart until the process is killed.

Steps to reproduce:
– Launch game via included .bat file
– Click “New Game” from the main menu
– Close the “Choose Initial Fleet” window using the X

Expected outcomes:
– Prompt for exit
– Return to main menu
– Process exits as if Exit was clicked

Actual outcomes:
– Process remains visible in task manager with no visible window
– Attempts to relaunch the game fail as it is already running