🧹 chore: pre-release cleanup 2

[danny-avila]

Summary

• Added a unique index for conversationId and user in the convoSchema to ensure data integrity and improve query performance.
• Created a new searchConversation function in the Conversation model to efficiently retrieve only necessary fields (conversationId and user) when validating conversation access.
• Updated the validateConvoAccess middleware to use the new searchConversation function, improving the efficiency of access validation.
• Refactored the scrollToEnd utility function in the client to remove the setTimeout delay, providing a better, more immediate, less prone to error effect
• Edited dynamic font sizes in style.css to use the font-size-base variable from 1rem for better consistency:
  • 🅰️ feat: Dynamic Font Size #3568 (comment)

Change Type

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Testing

To test these changes:

1. Verify that creating conversations with duplicate conversationId and user combinations is not possible.
2. Test the conversation access validation by attempting to access conversations with various user and conversationId combinations.
3. Check the performance of conversation queries, especially in scenarios with a large number of conversations.

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• I have commented in any complex areas of my code
• My changes do not introduce new warnings
• I have added necessary database indexes to improve query performance
• I have tested the changes to ensure they do not negatively impact existing functionality