oslog-logger-defaultslisted

# OSLog / `os.Logger` Defaults ## When to invoke - Starting a new Apple-platform project and picking a logging library. - Writing the first `Logger` declaration. - Deciding the default for privacy interpolation. - User asks "OSLog vs SwiftLog vs Sentry / CocoaLumberjack", "`.private` vs `.public` how to pick". ## Default decisions - **Use Apple's built-in `os.Logger`** (`import os`); **do not pull in any third-party logging library**. - Naming conventions: - `subsystem` = bundle ID (e.g. `com.example.myapp`) - `category` = module name (aligned with the SwiftPM target name) - **Privacy defaults to `.private`**: all string interpolation is treated as private; `.public` must be marked explicitly. ```swift import os extension Logger { static let engine = Logger(subsystem: "com.example.myapp", category: "Engine") } Logger.engine.info("user \(userId, privacy: .public) loaded puzzle \(puzzleId)") // ^^^^^^^ explicit public; puzzleId defaults to private ``` ## Rationale - Native integration with Console.app / Instruments / the unified logging system; zero dependencies. - Friendly to Swift 6 actor / Sendable. - Native privacy interpolation; `.private` content is automatically redacted in cross-device sysdiagnose. - No third-party SDK pulled in → no extra entries in `PrivacyInfo.xcprivacy`, consistent with the "no third-party tracking" stance. ### What `.private` actually means (easily misunderstood) - `.private` content is **redact