Problem
The CLI parses --config, but the main execution path does not load or apply the configuration. The configuration loader supports JSON only; TOML returns a not-implemented error, while project documentation also advertises YAML.
Proposed work
- Load the requested configuration before constructing discovery and runner options.
- Define precedence between defaults, configuration values, and CLI flags.
- Either implement TOML and YAML or narrow the documented supported formats.
- Validate unknown keys and invalid values with actionable errors.
- Add fixtures and end-to-end tests for supported formats and precedence.
Acceptance criteria
--config <file>affects an actual test run.- Supported formats are consistent across code, help text, and documentation.
- CLI flags override configuration values according to a documented rule.
- Invalid configurations fail clearly.