1.2.0

• Add --skip-end option to skip lines at the end of the input.
• Improve encoding detection: BOM-aware, strict UTF-8 validation,
  UTF-16 heuristic without BOM, fallback to chardet.
  Replaces the unmaintained to-utf-8 module.
• Surface the auto-detected encoding in the interpretation summary.
• Convert package to ESM ("type": "module").
• Upgrade dependencies (TypeScript 6, ESLint 10, yargs 18, csv-parse 6,
  csv-stringify 6, execa 9, fs-extra 11, tempy 3, Node types 25).
• Migrate ESLint config from .eslintrc.cjs to flat eslint.config.js.
• Add Nix flake for reproducible development environment (Node.js 24).