[Feature] Improve test coverage and strategy

[AmanatAliPanhwer]

🌟 Summary

Expand the test suite to cover more of the application's functionality and improve the overall testing strategy.

🧩 Problem or Motivation

The current test suite is a good start but has gaps in coverage. Key areas like authentication, video processing, and error handling are not fully tested.

🧰 Proposed Solution

• Unit Tests: Add unit tests for business logic in app.py and worker.py that does not require a full browser.
• Integration Tests: Add tests that verify the interaction between the Flask application and Supabase.
• Test Database Setup: Implement a dedicated test database setup (e.g., using an in-memory SQLite for unit/integration tests or a separate Supabase project for E2E) to ensure tests are isolated and do not affect the development or production environment.
• End-to-End (E2E) Tests:
  • Expand Playwright tests to cover user flows for authentication (login/logout).
  • Add tests for the video upload and processing flow (this may require mocking the external FFMPEG service).
  • Test edge cases and error conditions.
• Test Coverage: Configure pytest-cov to measure test coverage and set a target for improvement.
• CI: Ensure all tests are run automatically in the CI pipeline.

📦 Technical Considerations

• Frontend changes (HTML/JS/CSS)
• Backend changes (Flask, Supabase)
• Database changes
• Authentication/Authorization
• UI/UX improvements

🧠 Alternatives

N/A

🧾 Additional Context

A more robust test suite will increase confidence in code changes and reduce the risk of regressions.