Find untested code with a coverage audit, then generate pytest tests to close the gaps

Notes & tips

• Depend on the documented public surface. The supported API is the three workflow classes and their async execute, plus the WorkflowResult they return. Internal helpers (underscore- prefixed names, the AST/coverage parsing utilities) may change.
• Audit before you generate. Running test-audit first tells you where the gaps are so a test-gen pass spends its budget on the modules that matter.
• Keep runs cheap with path and depth. A quick pass over one module is far faster than a deep pass over src/.
• Single-module generation is most reliable via CLI / Python. Drive it with attune workflow run test-gen --path <module> or TestGenerationWorkflow().execute(path=<module>).