Add complete sound system with background music and localStorage pers…

[megha200479]

📌 Description

This PR adds a complete sound system to the Memory Block Game to improve gameplay interactivity and user engagement.

The implementation includes sound effects for game actions, background music, and persistent sound settings using localStorage.

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🔗 Related Issue

Closes: #87

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🛠 Changes Made

• Added card flip sound
• Added match success sound
• Added mismatch sound
• Added win/completion sound
• Added looping background music
• Implemented mute/unmute toggle
• Implemented volume slider
• Persisted sound preferences (volume + mute state) using localStorage
• Fixed image overflow issue to ensure character images remain inside cards
• Improved card reveal logic to support both image and emoji types

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Before:

• No sound feedback
• No background music
• Images could overflow card boundaries

After:

• Sound effects triggered on game actions
• Background music plays on user interaction
• Volume and mute state persist after page reload
• Images remain properly constrained within card layout

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✅ Checklist

• [✅] I have tested my changes
• [✅] My code follows project guidelines
• [✅] I have linked the related issue