lint

Run SwiftLint on the project using the existing config file: ``` swiftlint --config .swiftlint.yml ``` If SwiftLint is not installed, offer to install it via Homebrew: ``` brew install swiftlint ``` After linting, summarize: - Total warnings and errors - Files with the most violations - Any errors that must be fixed (errors block builds; warnings do not) If the user asks to auto-fix violations, run: ``` swiftlint --fix --config .swiftlint.yml ``` and report what was corrected vs. what still needs manual attention.