Implement BLE PIN pairing support for enhanced security

* Implement BLE pin pairing support with comprehensive tests and documentation

examples/ble_pin_pairing_example.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python3
+"""
+Example: BLE PIN Pairing with MeshCore
+
+This example demonstrates how to connect to a MeshCore device using BLE
+with PIN-based pairing for enhanced security.
+"""
+
+import asyncio
+import argparse
+from meshcore import MeshCore
+
+
+async def main():
+    parser = argparse.ArgumentParser(description="Connect to MeshCore device with BLE PIN pairing")
+    parser.add_argument("-a", "--addr", help="BLE address of the device (optional, will scan if not provided)")
+    parser.add_argument("-p", "--pin", help="PIN for BLE pairing (optional)")
+    parser.add_argument("--debug", action="store_true", help="Enable debug logging")
+    
+    args = parser.parse_args()
+    
+    try:
+        print("Connecting to MeshCore device...")
+        if args.pin:
+            print(f"Using PIN for pairing: {args.pin}")
+        
+        # Create BLE connection with optional PIN
+        meshcore = await MeshCore.create_ble(
+            address=args.addr,
+            pin=args.pin,
+            debug=args.debug
+        )
+        
+        print("✅ Connected successfully!")
+        
+        # Get device information to verify connection
+        result = await meshcore.commands.send_device_query()
+        if result.payload:
+            print(f"Device model: {result.payload.get('model', 'Unknown')}")
+            print(f"Firmware version: {result.payload.get('fw_version', 'Unknown')}")
+        
+        # Get device self-info
+        result = await meshcore.commands.send_appstart()
+        if result.payload:
+            print(f"Device public key: {result.payload.get('public_key', 'Unknown')[:16]}...")
+        
+        print("\nConnection test completed successfully!")
+        
+    except ConnectionError as e:
+        print(f"❌ Failed to connect: {e}")
+        return 1
+    except Exception as e:
+        print(f"❌ Error: {e}")
+        return 1
+    finally:
+        if 'meshcore' in locals():
+            await meshcore.disconnect()
+            print("Disconnected from device")
+    
+    return 0
+
+
+if __name__ == "__main__":
+    import sys
+    try:
+        sys.exit(asyncio.run(main()))
+    except KeyboardInterrupt:
+        print("\nInterrupted by user")
+        sys.exit(1)