feat: add BleRelayManager class skeleton

android/app/src/main/java/com/eddy/atomrelay/BleRelayManager.kt

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+package com.eddy.atomrelay
+
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCharacteristic
+import android.content.Context
+import android.os.Handler
+import android.os.Looper
+import java.util.UUID
+
+class BleRelayManager(
+    private val context: Context,
+    private val callbacks: BleCallbacks
+) {
+    companion object {
+        private val SERVICE_UUID: UUID = UUID.fromString("4fafc201-1fb5-459e-8fcc-c5c9c331914b")
+        private val CHARACTERISTIC_UUID: UUID = UUID.fromString("beb5483e-36e1-4688-b7f5-ea07361f26d8")
+        private val UUID_CHAR_UUID: UUID = UUID.fromString("beb5483e-36e1-4688-b7f5-ea07361f26d9")
+        private val CCCD_UUID: UUID = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb")
+        private const val SCAN_TIMEOUT_MS = 30000L
+        private const val RECONNECT_DELAY_MS = 2000L
+        private const val MAX_SCAN_RETRIES = 3
+    }
+
+    private var bluetoothGatt: BluetoothGatt? = null
+    private var relayCharacteristic: BluetoothGattCharacteristic? = null
+    private var isScanning = false
+    private var scanTimedOut = false
+    private var scanTimeoutRetries = 0
+    private val handler = Handler(Looper.getMainLooper())
+    private var seq = 1
+    private var hmacKey: ByteArray? = null
+    private var deviceUuid: ByteArray? = null
+    private var triedAddresses = mutableSetOf<String>()
+
+    fun startScan() {}
+    fun stopScan() {}
+    fun sendRelayCommand(cmd: Byte) {}
+    fun disconnect() {}
+    fun updateKeys() {}
+    fun resetTriedAddresses() {}
+    fun hasPermissions(): Boolean = false
+    fun getRequiredPermissions(): Array<String> = emptyArray()
+    fun destroy() {}
+}