Introduce new `grokkit lint` command for automatic language detection,
linting, and AI-suggested fixes. Supports 9 languages including Go, Python,
JavaScript, TypeScript, Rust, Ruby, Java, C/C++, and Shell.
- Add cmd/lint.go for command implementation
- Create internal/linter package with detection and execution logic
- Update README.md with usage examples and workflows
- Enhance docs/ARCHITECTURE.md and docs/TROUBLESHOOTING.md
- Add comprehensive tests for linter functionality