[Feature] Add linting with Ruff

[AmanatAliPanhwer]

🌟 Summary

Integrate Ruff into the development workflow to enforce code style and catch common errors.

🧩 Problem or Motivation

The codebase currently lacks an automated tool for ensuring code quality and consistency. This can lead to stylistic inconsistencies and potential bugs.

🧰 Proposed Solution

• Add Ruff to the project's development dependencies in pyproject.toml.
• Create a ruff.toml or pyproject.toml configuration file with sensible defaults, based on PEP 8.
• Add a script to pyproject.toml to run the linter (e.g., uv run lint).
• Integrate the linter into the CI/CD pipeline (.github/workflows/python-app.yml) to run on every push and pull request.
• Run an initial pass of the linter over the existing codebase and fix any reported issues.

📦 Technical Considerations

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

🧠 Alternatives

We could use other linters like flake8 or pylint, but Ruff is known for its speed and ease of configuration.

🧾 Additional Context

This will improve code quality and make the project easier to maintain.