feat: BLE 디버그 로거 — 펌웨어 디버깅용 상세 통신 로그

BleDebugLogger 신규:
- TX/RX 패킷 기록 (타임스탬프 ms, 데이터 크기)
- RSSI 실시간 추적 (5초마다 readRemoteRssi)
- 연결/끊김/재연결 이벤트 + GATT status code
- 패킷 타임아웃, 채널 누락, Endian 감지 로그
- 측정 결과 (volumeMl, lrRatio, validChannels)
- 파일 내보내기 (.log / .jsonl) + 클립보드 복사
- 세션 통계 (TX/RX/ERR/RSSI avg/min/max)

BleManager 연동:
- sendRaw() → TX 로그
- processReceivedData() → RX 로그
- connected/disconnected/reconnecting/reconnectFailed 이벤트
- onReadRemoteRssi 콜백 → RSSI 기록

PiezoMonitoringView:
- Developer Tools 하단에 BLE Debug Panel 추가
- 2초 자동 갱신, 색상 코딩 (TX=파랑, RX=초록, ERR=빨강, RSSI=노랑, CONN=보라)
- 클립보드 복사 / 파일 저장 / 클리어 버튼

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

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

@@ -52,6 +52,7 @@ class BleManager private constructor(private val context: Context) {
     private var txCharacteristic: BluetoothGattCharacteristic? = null
     private var rxCharacteristic: BluetoothGattCharacteristic? = null
     private val handler = Handler(Looper.getMainLooper())
+    val debugLogger = com.example.medilightv2android.services.BleDebugLogger.getInstance(context)
     private var scanTimer: Runnable? = null
     private var batteryTimer: Runnable? = null
     private var connectionTimer: Runnable? = null
@@ -265,8 +266,9 @@ class BleManager private constructor(private val context: Context) {
             loge { "sendRaw: bluetoothGatt is null!" }
             return
         }
-        val cmdPreview = if (data.size >= 4) String(data, 0, 4, Charsets.US_ASCII) else "?"
+        val cmdPreview = if (data.size >= 4) String(data, 0, 4, Charsets.US_ASCII).trimEnd('?') else "?"
         logd { "sendRaw: $cmdPreview (${data.size} bytes)" }
+        debugLogger.tx("$cmdPreview (${data.size}B)", data.size)
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
             val result = gatt.writeCharacteristic(characteristic, data, BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE)
             logd { "sendRaw result: $result" }
@@ -329,9 +331,11 @@ class BleManager private constructor(private val context: Context) {
     fun startBatteryPolling() {
         batteryTimer?.let { handler.removeCallbacks(it) }
         sendBatteryQuery()
+        bluetoothGatt?.readRemoteRssi()
         val poll = object : Runnable {
             override fun run() {
                 sendBatteryQuery()
+                bluetoothGatt?.readRemoteRssi()
                 handler.postDelayed(this, 5000)
             }
         }
@@ -349,6 +353,7 @@ class BleManager private constructor(private val context: Context) {
     private fun scheduleAutoReconnect() {
         if (reconnectAttempt >= maxReconnectAttempts) {
             logw { "Max reconnect attempts ($maxReconnectAttempts) reached" }
+            debugLogger.reconnectFailed()
             isReconnecting.value = false
             onReconnectionFailed?.invoke()
             return
@@ -356,6 +361,7 @@ class BleManager private constructor(private val context: Context) {
 
         val delay = reconnectDelays[reconnectAttempt.coerceAtMost(reconnectDelays.size - 1)]
         logd { "Auto-reconnect attempt ${reconnectAttempt + 1}/$maxReconnectAttempts in ${delay}ms" }
+        debugLogger.reconnecting(reconnectAttempt + 1, maxReconnectAttempts, delay)
         isReconnecting.value = true
 
         cancelReconnectTimer()
@@ -442,6 +448,7 @@ class BleManager private constructor(private val context: Context) {
                         lastConnectedAddress = gatt.device.address
                         reconnectAttempt = 0
                         cancelReconnectTimer()
+                        debugLogger.connected(connectedDeviceName.value, gatt.device.address)
 
                         try {
                             val prefs = context.getSharedPreferences("medilight_prefs", Context.MODE_PRIVATE)
@@ -468,6 +475,7 @@ class BleManager private constructor(private val context: Context) {
                         onConnectionStateChanged?.invoke(false)
 
                         if (!isUserDisconnect && lastConnectedAddress != null) {
+                            debugLogger.disconnected("unexpected", status)
                             onUnexpectedDisconnect?.invoke()
                             scheduleAutoReconnect()
                         }
@@ -562,19 +570,18 @@ class BleManager private constructor(private val context: Context) {
                 handler.post { processReceivedData(data) }
             }
         }
+
+        override fun onReadRemoteRssi(gatt: BluetoothGatt, rssi: Int, status: Int) {
+            if (status == BluetoothGatt.GATT_SUCCESS) {
+                handler.post { debugLogger.rssi(rssi) }
+            }
+        }
     }
 
     private fun processReceivedData(data: ByteArray) {
         val prefix = String(data, 0, minOf(4, data.size), Charsets.US_ASCII)
-        logd { "Received: $prefix (${data.size} bytes), callback=${
-            when {
-                prefix.startsWith("rcj") -> "onNirsMcjReceived=${onNirsMcjReceived != null}"
-                prefix.startsWith("rta") -> "onNirsPowerOnReceived=${onNirsPowerOnReceived != null}"
-                prefix.startsWith("rqq") || prefix.startsWith("rsh") -> "onNirsSensorActivated=${onNirsSensorActivated != null}"
-                prefix.startsWith("rag") -> "onNirsMagReceived=${onNirsMagReceived != null}"
-                else -> "n/a"
-            }
-        }" }
+        debugLogger.rx(prefix.trimEnd(':', '!'), data.size)
+        logd { "Received: $prefix (${data.size} bytes)" }
         when (prefix) {
             "rta:", "rta!" -> onNirsPowerOnReceived?.invoke()
             "rsh:", "rsh!", "rqq:", "rqq!" -> onNirsSensorActivated?.invoke()