Pick rest time on a 1-second wheel

Replaces the 5-second Steppers in Settings and the routine editor's
custom-rest row with a shared SecondsWheelRow: the row shows the value
and tapping it expands an inline wheel (10-180s, 1s steps) beneath.

Workouts/Views/Settings/SettingsView.swift

@@ -33,13 +33,7 @@ struct SettingsView: View {
             Form {
                 // MARK: - Workout Section
                 Section {
-                    Stepper(value: $restSeconds, in: 10...180, step: 5) {
-                        HStack {
-                            Text("Rest Between Sets")
-                            Spacer()
-                            Text("\(restSeconds)s").foregroundColor(.secondary)
-                        }
-                    }
+                    SecondsWheelRow(title: "Rest Between Sets", range: 10...180, seconds: $restSeconds)
 
                     Stepper(value: $doneCountdownSeconds, in: 3...20, step: 1) {
                         HStack {