fix: Settings 스크롤 + Placement Green 후 가이드 복귀

1. Settings 열면 화면 맨 위로 자동 스크롤 (animateScrollTo)
2. Placement Green 후 조건 벗어나면 isLocked=false → 가이드 다시 표시

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

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

@@ -614,10 +614,15 @@ fun PiezoMonitoringView(appState: AppState) {
             Spacer(modifier = Modifier.height(8.dp))
         }
 
+        val scrollState = rememberScrollState()
+        LaunchedEffect(showSettings) {
+            if (showSettings) scrollState.animateScrollTo(0)
+        }
+
         Column(
             modifier = Modifier
                 .weight(1f)
-                .verticalScroll(rememberScrollState())
+                .verticalScroll(scrollState)
                 .padding(horizontal = hPad)
                 .padding(top = if (isCompact) 8.dp else 16.dp, bottom = if (isCompact) 16.dp else 32.dp),
             horizontalAlignment = Alignment.CenterHorizontally,

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

@@ -362,6 +362,7 @@ fun PlacementGuideView(appState: AppState) {
                             bleManager.sendLedMode(6) // ALIGN_COMPLETE
                             bleManager.debugLogger.info("PLACEMENT_GREEN cv=${"%.3f".format(guideResult.cv)} lr_dev=${"%.3f".format(guideResult.lrDev)} score=${guideResult.score}")
                         } else {
+                            isLocked = false  // Green 벗어나면 다시 가이드
                             bleManager.sendLedMode(5) // ALIGN_SEARCHING
                             bleManager.debugLogger.info("PLACEMENT_${guideResult.phase.name} score=${guideResult.score} hint=${guideResult.hint}")
                         }