refactor: remove ESLint, use Biome exclusively

- Uninstall eslint, @typescript-eslint/eslint-plugin, @typescript-eslint/parser
- Remove .eslintrc.json configuration file
- Remove eslint-disable comments from source files
- Reduces dependencies from 353 to 283 packages (-70 packages)
- Biome now handles all linting and formatting

This completes the migration from ESLint to Biome.

Author: Hi7cl4w