feat: redesign bench calibration (factor/offset), add Ttank/P2 displays, fix sensor calibration

- Replace P1-P6 rational transfer function with factor/offset model for bench params
- Add explicit rx/tx direction flags in bench XML configuration
- Add T.Tank (BenchTemp) and P2 (AnalogSensor2) to temperature/pressure display
- Apply SensorConfiguration calibration to pressure channels, fix empty sensors.xml fallback
- Add live value labels to flowmeter charts
- Hide pump live values and PSG encoder standalone label
- Add K-Line connection state model, improve KWP service and status displays
- Restructure .claude/skills into subdirectory format

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Infrastructure/Kwp/KW1281Connection.cs

@@ -299,7 +299,9 @@ namespace HC_APTBS.Infrastructure.Kwp
             {
                 var packet = ReceivePacket();
 				packets.Add(packet); // TODO: Maybe don't add the packet if it's an Ack
-				if (packet is AckPacket || packet is NakPacket)
+                //SendAckPacket();
+
+                if (packet is AckPacket || packet is NakPacket)
                 {
                     break;
                 }