UX: 수기 입력 기본값을 현재 추정 용량(estimatedVolume)으로 설정

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PiezoMonitoringView.kt

@@ -163,7 +163,7 @@ fun PiezoMonitoringView(appState: AppState) {
 
     // 수기 입력 다이얼로그
     if (showManualInput) {
-        var volumeText by remember { mutableStateOf("") }
+        var volumeText by remember { mutableStateOf(appState.estimatedVolume.toString()) }
         AlertDialog(
             onDismissRequest = { showManualInput = false },
             title = { Text("소변량 입력") },
@@ -172,7 +172,7 @@ fun PiezoMonitoringView(appState: AppState) {
                     OutlinedTextField(
                         value = volumeText,
                         onValueChange = { volumeText = it.filter { c -> c.isDigit() }.take(4) },
-                        placeholder = { Text("예: 200") },
+                        placeholder = { Text("예: ${appState.estimatedVolume}") },
                         keyboardOptions = androidx.compose.foundation.text.KeyboardOptions(keyboardType = androidx.compose.ui.text.input.KeyboardType.Number),
                         singleLine = true,
                         modifier = Modifier.weight(1f)