[FEATURE] Refactor Phase 2: Migrate UI scripts

[ikostan]

Task 2: Migrate UI Scripts

---

name: Feature Request
about: Move all UI-related scripts to the new UI directories
title: '[FEATURE] Refactor Phase 2: Migrate UI scripts'
labels: enhancement, refactor
assignees: ''

Description:
Move all user interface scripts into their respective subfolders within res://scripts/ui/.

Why is this useful?
UI scripts make up the bulk of the loose files. Isolating menus, individual components, and screens makes it easier to find specific frontend logic.

Proposed Implementation:
Using the Godot Editor (Drag and Drop):

1. Move to ui/menus/: advanced_settings.gd, main_menu.gd, options_menu.gd, pause_menu.gd, audio_settings.gd, gameplay_settings.gd, key_mapping.gd.
2. Move to ui/components/: input_remap_button.gd, volume_slider.gd.
3. Move to ui/screens/: loading_screen.gd, splash_screen.gd.

Additional Context:
Wait for Godot to re-import and update dependencies after each batch move to ensure .uid links remain intact.