- Add ESLint 9 flat config (eslint.config.mjs) with typescript-eslint
recommended rules and eslint-config-prettier
- Add lint-staged to run eslint+prettier only on staged files
- Update pre-commit hook to use lint-staged instead of full prettier check
- Add `lint` and `format:check` scripts to package.json
- Add Lint step to CI workflow
- Fix resulting lint errors: unused vars (_ctx, _options, catch binding),
any→unknown in type declarations, stale eslint-disable comments
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>