fix: score extensionless configured files

[mkdev5]

Summary

Score configured extensionless files like Dockerfile and Makefile.

FileChange._calculate_file_extension() previously returned an empty string for basenames without a dot. As a result, files such as Dockerfile, dockerfile, Makefile, and makefile could not reach the configured tree-sitter scoring path, even though programming_languages.json defines dockerfile and makefile.

This PR normalizes those configured extensionless basenames to their language config keys, while preserving existing behavior for normal dotted files and unrelated extensionless files.

Related Issues

Closes #985

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other (describe below)

Testing

• Tests added/updated

• Manually tested

• ./.venv/bin/pytest tests/test_classes.py::test_file_extension_handles_configured_extensionless_filenames tests/validator/test_token_scoring_integration.py::TestTreeDiffScoring::test_configured_extensionless_files_reach_tree_diff -q

• ./.venv/bin/pytest tests/test_classes.py tests/validator/test_token_scoring_integration.py tests/validator/test_base_score.py -q

• uv run pytest tests/ -q

• uv run ruff check

• uv run ruff format --check

• uv run pyright

Checklist

• Code follows project style guidelines
• Self-review completed
• Changes are documented (if applicable)

[anderdc]

Move _EXTENSIONLESS_FILE_EXTENSIONS to gittensor/constants.py alongside NON_CODE_EXTENSIONS — both are extension-keyed scoring config and should colocate. Import it from there in classes.py.

[mkdev5]

Move _EXTENSIONLESS_FILE_EXTENSIONS to gittensor/constants.py alongside NON_CODE_EXTENSIONS — both are extension-keyed scoring config and should colocate. Import it from there in classes.py.

done