Add AI engine coverage reporting to CI (run tests with coverage, show in step summary, and upload artifact). Relax and align engine pre-commit package specifiers and update uv.lock. Increase ruff line-length and add per-file ignores; update Taskfile and pre-commit Taskfile to use engine ruff config. Add coverage entries to engine/.gitignore. Apply numerous non-functional Python style and formatting fixes across scripts and cucumber test steps (imports, f-strings, line breaks, noqa markers, single-line asserts) to satisfy linters—no behavioral changes intended.