Implement basic testing and quality assurance

[coderabbitai]

Objective

Add essential testing to ensure SocrAI works correctly before launch.

Tasks

• Add frontend unit tests for critical components
• Add backend API tests for conversation and message endpoints
• Test all three pill modes with various programming languages
• Implement error handling for OpenAI API failures
• Test user authentication flow
• Create a manual testing checklist for pre-launch verification

Why this is important

Testing is crucial to ensure users have a smooth experience when using SocrAI for the first time.

References

• This issue was created from PR: impro #6