feat: add subject search functionality

[gayatripadalia]

Related Issue

Fixes #319

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Description

This PR adds a search functionality to improve navigation across subjects.

Changes made:

• Added a search bar to the Browse Subjects section.
• Users can search by subject name or semester.
• Implemented case-insensitive live filtering.
• Added direct navigation to the selected subject.
• Displays a user-friendly message when no matching subject or semester is found.

This feature helps users quickly locate subjects without manually browsing through each semester.

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Type of Change

• Bug fix
• New feature
• Documentation update
• UI/UX improvement
• Refactor

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Screenshots / Demo

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How Has This Been Tested?

Tested locally using the Next.js development server.

Verified the following:

• Search returns matching subjects.
• Search returns matching semesters.
• Search is case-insensitive.
• Clicking a search result navigates to the corresponding subject page.
• Displays an appropriate message when no matching subject or semester is found.

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Checklist

• My code follows the project structure and conventions
• I have tested the changes locally
• I have linked the related issue properly
• I have added screenshots where applicable
• No existing functionality was broken

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Additional Notes

Currently, the search supports subject names and semester names. This provides quicker navigation across the available subjects and can be extended in the future to support searching by topics and keywords within notes.

[vercel]

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