🔄 反转行号 stepper：+上移 -下移

Sources/FloatingMonitor/Views/SettingsView.swift

@@ -121,8 +121,14 @@ struct SettingsView: View {
                 .font(.system(size: 11))
                 .frame(width: 26, alignment: .leading)
 
-            // 行号 stepper
+            // 行号 stepper（+向上 -向下）
-            Stepper("", value: row, in: 1...10)
+            Stepper {
+                Text("")
+            } onIncrement: {
+                if row.wrappedValue > 1 { row.wrappedValue -= 1 }
+            } onDecrement: {
+                if row.wrappedValue < 10 { row.wrappedValue += 1 }
+            }
             .labelsHidden()
             .scaleEffect(0.7)
             .frame(width: 24)