Implemented the missing scripts required by the audit-agent:
- `scripts/check-file-size.mjs`: Checks for files exceeding 300 lines.
- `scripts/check-innerhtml.mjs`: Checks for `innerHTML` usage.
- Added `npm run lint` script using ESLint with a basic configuration.
- Added `eslint` and related dependencies.
This unblocks the audit-agent daily schedule.
Co-authored-by: PR0M3TH3AN <[email protected]>
