Adjust rest time from the watch with the same 1-second stepper

A gear on the watch root opens a small Settings sheet whose stepper
edits the shared restSeconds default (10-180s, 1s steps). Edits ride a
new settingsUpdate message to the phone - debounced per stepper burst,
falling back to transferUserInfo when unreachable - which clamps the
value, writes the shared default, and re-echoes it to every device
through the application context. While an edit is pending on the watch,
an in-flight context's stale rest value is skipped so it can't yank the
stepper back mid-edit.

Workouts Watch App/WatchScreenshotRoot.swift

@@ -30,6 +30,8 @@ struct WatchScreenshotRoot: View {
                 ProgressHost(workout: workout, exerciseName: "Lat Pulldown", page: 0)
             case "rest":
                 ProgressHost(workout: workout, exerciseName: "Lat Pulldown", page: 1)
+            case "settings":
+                NavigationStack { WatchSettingsView() }
             default:
                 NavigationStack { WorkoutLogListView(workout: workout) }
             }