Improve test coverage for convert.py with edge case scenarios

[theanand108]

Summary

This PR improves test coverage for convert.py by adding unit tests targeting previously uncovered edge cases and error-handling paths.

Changes

Added tests for:

• _parse_mapping_file

  • Exception handling during YAML parsing

• _validate_file_paths

  • Output directory outside allowed base path

• _convert_with_docx2pdf

  • Successful conversion scenario
  • Exception during import/conversion

• _rename_libreoffice_output

  • File renaming behavior when output already exists

• create_edition_from_template

  • DOCX flow ensuring document is processed and saved correctly

• main

  • Handling when PDF conversion is requested but not supported

Notes

• No functional code changes were made
• Existing tests remain unaffected
• Focused only on improving coverage and robustness of edge cases

Impact

• Improves reliability of conversion workflows
• Increases confidence in error handling paths
• Helps maintain high overall test coverage

AI Disclosure

Parts of this contribution were developed with the assistance of AI tools (ChatGPT) for guidance on test design and edge case identification. All code has been reviewed, tested, and validated by the author.

Affirmation

• My code follows the CONTRIBUTING.md guidelines