Fix: prevent Snake game from re-rendering and add score tracking

[KORandi]

Add standalone game support configuration + showing score tracking for Snake game at the end screen

Previous Behaviour

• Snake game was treated like regular games with multiple rounds
• Displayed "Round 1/10" instead of "Round 1/1"
• After finishing game, jumped to "Round 10/10" and showed menu in background
• Game restarted automatically and user had to either finish it again or use mouse to click terminal (at least on macOS)
• Score was not displayed at end of game
• Statistics were incorrectly calculated for Snake

Expected Behaviour

• Standalone games (currently only Snake) display "Round 1/1" during gameplay
• When game ends, display "Game finished!" and final score
• Game does not restart automatically
• Menu appears properly after game completion
• Score is properly logged in statistics
• No round statistics should be shown for standalone games

Previously

End screen re-renders Snake game

Showing 1/10 rounds

After the fix

End screen now correctly shows score

During the run it shows 1/1 rounds