[Feature] [Server]: add auth cache invalidation and update contribution policies

[Gautam25Raj]

Summary

This pull request strengthens authentication cache consistency by introducing additional cache invalidation mechanisms and updates the project's contribution guidelines to establish clearer issue claiming and pull request expectations for contributors.

What's Changed

✨ Authentication Improvements

• Added cache invalidation hooks for user and session deletion events within the authentication module.
• Implemented token-based cache invalidation support in the authentication cache utility.
• Improved cache consistency across authentication-related operations to reduce the risk of stale session or user data.

📚 Community & Documentation

• Enhanced contribution guidelines with stricter issue claiming requirements and pull request policies.
• Updated the README to reflect the latest contribution workflow and community expectations.
• Improved contributor guidance to help streamline collaboration and reduce duplicate work.

Notes

• No breaking changes are introduced.
• These changes improve authentication reliability while providing a more structured contribution process for the community.

Linked Issues

• Fixes [FEATURE]: Automated Redis session cache invalidation via Prisma database hooks #158

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📝 Documentation update
• 🧪 Tests (adding or updating tests)

Checklist

• I have read the CONTRIBUTING.md document.
• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• Any dependent changes have been merged and published in downstream modules.