Module params 

2026-09-26: Parameter schema: what a benchmark exposes for editing before it runs.

A benchmark declares ParamSpecs; the TUI renders them, the user edits them as text, and the edited ParamValues reach Benchmark::configure before the first next(). ParamValues::defaults takes the starting values from the specs, and the TUI’s edit form parses through ParamKind::parse.

Owner: bench (parameters). Invariants:

• ParamKind::parse returns only values inside the kind’s domain.
• ParamValues accessors never substitute a value for a missing or mistyped key.

Structs

ParamSpec

2026-09-26: One editable parameter.

ParamValues

2026-09-26: The edited values handed to Benchmark::configure.

Enums

ParamKind

2026-09-26: The editing affordance and the validation domain for one parameter.

ParamValue

2026-09-26: A concrete parameter value.