By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Render the diff runner's progress line as coloured chunks The diff-scoped runner's one-line "N changed hunks; selected M mutations" message went out via plain `hPutStrLn`. Render it through `[[Chunk]]` with `hPutChunksLocaleWith` (cyan hunk count, green mutation count, correct singular/plural), matching the coverage and mutation phases' coloured output. The machine-readable stdout of `list-components` and the `--mutation-coverage-list[-locations]` modes is intentionally left plain: it is parsed by the driver and Nix harness, so it must not carry colour codes.