feat: Distance/Sample 슬라이더→숫자 직접 입력으로 변경

OutlinedTextField + Decimal 키보드로 정밀 입력 가능
범위: 0.5~5.0mm, 기본값 1.771mm
입력 즉시 PiezoHW.distancePerSample 반영

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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

@@ -662,22 +662,32 @@ fun PiezoMonitoringView(appState: AppState) {
 
                         HorizontalDivider()
 
-                        // Distance Per Sample
-                        var currentDps by remember { mutableStateOf(PiezoHW.distancePerSample.toFloat()) }
+                        // Distance Per Sample (직접 입력)
+                        var dpsText by remember { mutableStateOf("%.3f".format(PiezoHW.distancePerSample)) }
                         Row(verticalAlignment = Alignment.CenterVertically) {
                             Text("Distance/Sample", fontSize = 14.sp, fontWeight = FontWeight.SemiBold)
                             Spacer(modifier = Modifier.weight(1f))
-                            Text("${"%.3f".format(currentDps)} mm", fontSize = 14.sp, fontWeight = FontWeight.Bold, color = Color(0xFF4CAF50))
+                            OutlinedTextField(
+                                value = dpsText,
+                                onValueChange = { input ->
+                                    dpsText = input
+                                    input.toDoubleOrNull()?.let { v ->
+                                        if (v in 0.5..5.0) PiezoHW.distancePerSample = v
+                                    }
+                                },
+                                suffix = { Text("mm", fontSize = 12.sp, color = MlSecondaryText) },
+                                singleLine = true,
+                                keyboardOptions = androidx.compose.foundation.text.KeyboardOptions(
+                                    keyboardType = androidx.compose.ui.text.input.KeyboardType.Decimal
+                                ),
+                                modifier = Modifier.width(120.dp),
+                                textStyle = androidx.compose.ui.text.TextStyle(
+                                    fontSize = 14.sp,
+                                    fontWeight = FontWeight.Bold,
+                                    color = Color(0xFF4CAF50)
+                                )
+                            )
                         }
-                        Slider(
-                            value = currentDps,
-                            onValueChange = {
-                                currentDps = it
-                                PiezoHW.distancePerSample = it.toDouble()
-                            },
-                            valueRange = 1.5f..2.5f,
-                            colors = SliderDefaults.colors(thumbColor = Color(0xFF4CAF50), activeTrackColor = Color(0xFF4CAF50))
-                        )
 
                         HorizontalDivider()