chore: CI setup

[lmiguelvargasf]

What does this PR do?

It integrates two workflows:

• PR Validation - Enforce PR title conventions and limit PR size.
• CI - Run tests and linting on both frontend and backend.

Related Issues

N/A

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Refactoring (code improvements without changing behavior)
• Performance improvement
• Other (please specify): ________________

How has this been tested?

• Through GitHub Actions

Screenshots or Videos (if applicable)

N/A

Checklist

• Code follows the project's coding style guidelines
• Tests have been added or updated for these changes
• All tests pass locally
• Documentation has been updated where necessary
• Changes do not introduce new warnings or errors

Additional Context

N/A

Reviewer Notes (optional)

N/A

[gitguardian]

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