Develop BDD Tests for gitflow Scripts using ShellSpec

[ChrisJStone]

Create behavior-driven development (BDD) tests for each gitflow script using ShellSpec. Link this sub-issue to the parent Test Suite issue.

Code references:

• Review the Project Status and Next Steps section for modernization goals.
• Identify entrypoint and script behaviors in existing shell code (legacy branches).

Please specify:

• Priority scripts to test
• Example scenarios/workflows for BDD coverage
• Expected shell behaviors for BDD coverage

This sub-issue is part of the comprehensive Test Suite refactor.