fix: remove broad exception swallowing in main()

[pipe1os]

Summary

Removes broad exception swallowing in the CLI entrypoint.

Motivation & Context

The main function in cli.py previously wrapped its core logic in broad except Exception as e: blocks that swallowed stack traces. This change removes those blocks to allow unexpected exceptions to surface naturally at the CLI boundary, improving debuggability by ensuring standard Python tracebacks are visible.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactoring (no functional changes, no api changes)
• Documentation update

How Has This Been Tested?

Ran PYTHONPATH=src pytest to verify that no existing tests relied on the exception swallowing exit code behavior. Verified that manual errors now surface a full traceback.

• Unit tests
• Integration tests
• Manual testing

Checklist

• My code follows the code style of this project.
• My commit messages follow the Conventional Commits format, are lowercase, imperative, and specific.
• I have updated the documentation accordingly (if applicable).
• I have added tests to cover my changes.
• All new and existing tests passed.