Make GitHub Project operations explicit

[codeforester]

Summary

• Add an explicit ProjectOperations container for GitHub Project command helpers.
• Replace sys.modules[__name__] module-as-ops coupling with project_operations().
• Add a structure test that keeps the operations object explicit.

Closes #1465

Validation

• PYTHONPATH=lib/python:cli/python $HOME/.base.d/base/.venv/bin/python -m pytest cli/python/base_github_projects/tests/test_engine_structure.py::test_project_operations_are_explicit_instead_of_module_ops -q
• PYTHONPATH=lib/python:cli/python $HOME/.base.d/base/.venv/bin/python -m pytest cli/python/base_github_projects/tests/test_engine.py cli/python/base_github_projects/tests/test_project_configure_replacement.py -q
• PYTHONPATH=lib/python:cli/python $HOME/.base.d/base/.venv/bin/python -m pytest cli/python/base_github_projects/tests -q
• PYTHONPATH=lib/python:cli/python $HOME/.base.d/base/.venv/bin/python -m pylint cli/python/base_github_projects/engine.py cli/python/base_github_projects/project_operations.py cli/python/base_github_projects/tests/test_engine_structure.py
• PYTHONPATH=lib/python:cli/python $HOME/.base.d/base/.venv/bin/python -m compileall -q cli/python/base_github_projects/engine.py cli/python/base_github_projects/project_operations.py cli/python/base_github_projects/tests/test_engine_structure.py
• git diff --check
• env BASE_BASH_LIBS_DIR=/Users/rameshhp/work/base-bash-libs/lib/bash BASE_CACHE_DIR=/private/tmp/base-1465-project-smoke bin/basectl gh project doctor --project base --owner basefoundry