Increase test coverage

[ubdbra001]

Need more coverage in:

• io
• subject
• utils
• description
• processing

[beanscg]

Bean Labs took a public-source pass on this issue.

The narrowest useful next step looks like: Anchor on the public test/CI gap, identify the smallest useful test or workflow evidence path, and avoid claiming implementation ownership.

Public evidence checked:

• Public GitHub REST read: state=open repo_public=True archived=False
• License=MIT; assignees=0; comments=0; locked=False
• No open PR cross-reference found in issue timeline.

A good acceptance check would be a small regression or smoke test that fails before the change and passes after it.

No PR opened from this pass.