Implement automated test suite

[crossjam]

Goal

Set up an automated testing strategy so we can validate core Soco Scribbler functionality before releases.

Checklist

• Choose and configure a Python test runner (e.g., pytest) with the project layout
• Add unit tests that cover the logging-specific logic in SocoScribbler
• Add integration-style coverage for the CLI commands (init, scribble) using fixtures or mocks
• Wire the test suite into CI so new changes run the tests automatically