fix: mbb 측정 복원 — PiezoPacketCollector가 rbb: 헤더를 skip하도록 수정

근본 원인: mbb? 응답에서 rbb: 헤더가 먼저 오는데 collector가 모르고 무시
→ onMultiChannelComplete 콜백 안 불림 → isMeasuring 영구 true → 버튼 비활성화

수정:
- PiezoPacketCollector.addPacket(): rbb: prefix 인식 → skip + 로그
- BleManager: rbb: 수신 시 piezoCollector.addPacket()에도 전달
- PiezoMonitoringView: sendChannelsOnly→sendFullMeasurement(mbb) 복원

흐름: mbb? → rbb:(skip) → reb:×6(수집) → raa:(완료) → 콜백 정상

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

app/src/main/java/com/example/medilightv2android/ble/BleManager.kt

@@ -816,6 +816,7 @@ class BleManager private constructor(private val context: Context) {
             "rbb:" -> {
                 debugLogger.rx("rbb", data.size, "full measurement header (battery+IMU+temp)")
                 onMbbHeaderReceived?.invoke(data)
+                piezoCollector.addPacket(data)
             }
             "rsp:" -> {
                 if (data.size >= 16) {

app/src/main/java/com/example/medilightv2android/ble/PiezoPacketCollector.kt

@@ -64,6 +64,9 @@ class PiezoPacketCollector {
 
         val prefix = String(data, 0, 4, Charsets.US_ASCII)
         when (prefix) {
+            "rbb:" -> {
+                onLog?.invoke("rbb: header skipped (${data.size}B) — waiting for reb:")
+            }
             "reb:" -> processRebPacket(data)
             "red:" -> processRedPacket(data)
             "ree:", "raa:" -> processEndPacket(prefix, data)

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

@@ -181,7 +181,7 @@ fun PiezoMonitoringView(appState: AppState) {
         }
         bleManager.piezoCollector.onLog = { msg -> Log.d("PiezoCollector", msg) }
 
-        bleManager.sendChannelsOnly()
+        bleManager.sendFullMeasurement()
 
         // Timeout with auto-retry (15s)
         handler.postDelayed({
@@ -190,7 +190,7 @@ fun PiezoMonitoringView(appState: AppState) {
                 measureRetryCount++
                 Log.w("PiezoMonitor", "Timeout — auto-retry $measureRetryCount/$maxMeasureRetries")
                 bleManager.piezoCollector.reset()
-                bleManager.sendChannelsOnly()
+                bleManager.sendFullMeasurement()
                 // Second timeout for retry
                 handler.postDelayed({
                     if (!isMeasuring) return@postDelayed