Update docstrings

Trio/Sources/APS/OpenAPS/OpenAPS.swift

@@ -209,6 +209,8 @@ final class OpenAPS {
             }
 
             // This condition addresses https://github.com/nightscout/Trio/issues/898
+            // If onboardingCompletedAt is present, we know it is a fresh install,
+            // as we only store this computed timestamp for new Trio users.
             // Fresh installs usually do not have any pump history, so the first
             // event after onboarding is typically a PumpResume. Without a preceding
             // suspend, oref interprets the time between midnight and onboarding as lacking

Trio/Sources/Modules/Onboarding/OnboardingStateModel.swift

@@ -44,7 +44,7 @@ extension Onboarding {
 
         // MARK: - Determine Initial Build State
 
-        /// Determines whether the app is in a fresh install state for Trio v0.3.0.
+        /// Determines whether the app is in a fresh install state for Trio (new vs. returning/updating user).
         ///
         /// This check is based on the assumption that a truly clean install will only contain
         /// the `logs/` directory and the `preferences.json` file in the app's Documents directory.