Remove leftovers of old splash screen

[Copilot]

This PR removes all remaining artifacts from an old splash screen implementation that was no longer being used in the main game flow.

Changes Made

• Removed ui/splash.gd - Old splash screen script that was misleadingly named
• Removed ui/splash.gd.uid - Associated UID file for the old splash script
• Created ui/credits.gd - New properly named script for credits functionality
• Updated ui/credits.tscn - Now references the correct credits.gd script instead of the old splash script
• Renamed functions - Changed exit_splash() to exit_credits() for semantic clarity

Context

The repository had leftover files from an old splash screen implementation. The splash.gd script was actually being used by the credits screen (credits.tscn) but retained the old splash-related naming, which was confusing and misleading.

The main game flow already bypassed any splash screen (project starts directly with main.tscn), so these were truly just leftovers that needed cleanup.

Verification

• ✅ No files named *splash* remain in the repository
• ✅ No textual references to "splash" exist in any code files
• ✅ Credits screen functionality remains intact
• ✅ Credits still display for 10 seconds or until user input, then return to main scene

Fixes #1.

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[Copilot]

Pull Request Overview

Removes leftover splash screen artifacts and properly renames and hooks up the credits functionality.

• Deleted outdated splash script and its UID file
• Updated scene to reference the new credits.gd script
• Renamed exit_splash() to exit_credits() for semantic clarity

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
ui/splash.gd.uid	Removed obsolete splash screen UID file
ui/credits.tscn	Updated script reference from splash.gd to credits.gd
ui/credits.gd	Renamed exit_splash() to exit_credits() and updated calls

Comments suppressed due to low confidence (1)

ui/credits.gd:14

• Currently the keyboard input branch exits on any key event, including key release. To match the mouse branch, wrap this call in if event.is_pressed(): so it only triggers on key press.

exit_credits()