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>

Views/UserControls/PumpIdentificationView.xaml

@@ -94,6 +94,8 @@
                 <StackPanel Grid.Column="1" VerticalAlignment="Center" Margin="6,0,0,0">
                     <Button Content="Read K-Line" Width="90" Margin="0,2"
                             Command="{Binding ReadKlineCommand}"/>
+                    <Button Content="Disconnect" Width="90" Margin="0,2"
+                            Command="{Binding DisconnectKLineCommand}"/>
                     <!-- Progress bar shown during K-Line read -->
                     <ProgressBar Value="{Binding ProgressPercent, Mode=OneWay}"
                                  Minimum="0" Maximum="100" Height="6"