Improve game play

[MsteR7]

This pull request introduces several improvements and bug fixes to the space shooter game's level loading, background rendering, sound handling, score tracking, and menu system. The main focus is on supporting both solo and multiplayer modes more robustly, improving user interface elements, and ensuring sounds and scores are handled correctly depending on the game mode.

Multiplayer and Solo Mode Handling:

• All level scripts (Level-1.lua through Level-5.lua) now dynamically select the background texture based on whether the game is in solo or multiplayer mode, ensuring the correct visuals are shown for each mode.
• The background creation function (Spawns.createBackground) now accepts optional scaling parameters, allowing backgrounds in multiplayer mode to be rendered larger for better screen coverage.

Sound and Score System Enhancements:

• Sound effects for player hits, explosions, power-ups, and game over are now correctly played locally in solo mode and broadcasted to all clients in multiplayer mode, ensuring consistent audio feedback.

• Score tracking has been improved so that when an enemy is destroyed, the player who fired the bullet receives the appropriate score, in addition to the global score increment. Bullets now track their owner's ID.

Menu and UI Improvements:

• The main menu's button colors, text centering, and spacing have been updated for better appearance and usability. The solo button is now purple, button widths are increased, and text centering is more precise.

• A new helper function ensures a clean start when switching game modes (SOLO/MULTI), stopping music and destroying entities as needed.

Bug Fixes and Edge Case Handling:

• Enemy deaths due to leaving the play area (boundary deaths) no longer trigger network broadcasts or local explosions, preventing unnecessary effects and network traffic.

• Level 5 background handling is clarified to use the same texture for both solo and multiplayer modes.

Other Minor Improvements:

• Minor cleanup in level and menu scripts for consistency and maintainability.

Quick metadata (pick one in each group)

Impact:

• impact:high
• impact:medium
• [ x ] impact:low

Priority:

• priority:important
• priority:story
• [ x ] priority:no-priority
• priority:bonus

Type / Area:

• type:game-engine
• type:new-module
• [ x ] type:server-dev
• [ x ] type:client-dev
• [ x ] type:ui-asset-visual

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Checklist

• documentation check
• follow repo rule check
• i tested all my change.

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Reviewer notes

Files changed and quick description: