fix: notifications pagination + dropdown updates

[Anshpujara5]

Description

Adds pagination to the notifications system so notifications load in batches instead of all at once.

Backend pagination parameters (page, limit) are verified and used correctly, and the frontend notification dropdown now supports incremental loading via a Load More button. This improves performance and provides a smoother user experience for users with large notification histories.

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Type of Change

• Bug fix
• New feature

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Related Issues

Closes #13

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Testing

• Tested locally
• Client build (npm run build) passes successfully
• Client lint reports existing repository-wide lint issues unrelated to this PR
• Server has no lint script; notifications endpoint tested manually

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Screenshots

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Checklist

• Code follows existing project style guidelines
• Self-reviewed the code
• Added comments for complex logic where needed
• Documentation update not required for this change

[Anshpujara5]

Hi @tarinagarwal 👋

Just a gentle follow-up regarding this PR.
Whenever you get a chance, could you please review it and let me know if any changes are required from my side?

I’m happy to iterate or make updates as needed.
Thanks for your time and guidance 😊

[tarinagarwal]

@Anshpujara5 Hey! ill review this pr asap, sorry for the delay