Add swiftlint and swiftformat with CI, fix quoted CLI output
- Add .swiftlint.yml and .swiftformat with reasonable defaults
- Add CI workflow running lint + format check + tests on push/PR
- Run swiftlint --fix and swiftformat across entire codebase
- Fix modifier order (nonisolated before private)
- Fix debugPrint → print in all CLI commands (debugPrint wraps
output in quotes, which is wrong for user-facing CLI output)