feat: redesign Pump page with Fluent card layout, bottom snackbar, and RPM chart

- Replace sub-nav + HiddenTabsTabControl with 3-column Fluent card layout:
  PumpCommandsCard (vertical ME/FBKW/PreIn sliders) + DfiCalibrationCard /
  PumpLiveDataCard (KPI tiles + RPM rolling chart + redesigned status bytes) /
  PumpIdentificationCard + DtcCard
- Add PumpTopStripView: pump selector, model badge, CAN + K-Line chips
- Move immobilizer unlock to MainWindow bottom snackbar (UnlockSnackbarView):
  auto-close on success after 3 s, persist on failure with manual Dismiss
- Redesign StatusDisplayView to 2×8 rounded 28px tiles with bit index + tooltip
- Add NullToVisibilityConverter; add SnackbarShell, PumpCard, and related styles
- Delete obsolete views: UnlockProgressDialog, UnlockPanelView,
  PumpIdentificationPanelView, PumpLiveDataView, DfiManageView,
  DtcListView, PumpControlView
- PumpPageViewModel: remove PumpSubPage enum, add RpmChart wired to Root.PumpRpm

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

ViewModels/StatusDisplayViewModel.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.ObjectModel;
+using System.Linq;
 using CommunityToolkit.Mvvm.ComponentModel;
 using HC_APTBS.Models;
 
@@ -64,6 +65,9 @@ namespace HC_APTBS.ViewModels
         /// <summary>16 bit indicators for bits 0–15 of the current status word.</summary>
         public ObservableCollection<BitIndicatorViewModel> Bits { get; } = new();
 
+        /// <summary>Number of bits currently active (set to 1) in the status word.</summary>
+        public int ActiveCount => Bits.Count(b => b.IsActive);
+
         /// <summary>
         /// Fired when a bit that is flagged as an error transitions to active.
         /// The argument is the bit position (0-based).
@@ -119,6 +123,8 @@ namespace HC_APTBS.ViewModels
                 if (isSet && statusBit.Enabled)
                     ErrorBitDetected?.Invoke(index);
             }
+
+            OnPropertyChanged(nameof(ActiveCount));
         }
 
         /// <summary>Resets all indicators to the default green / inactive state.</summary>
@@ -130,6 +136,8 @@ namespace HC_APTBS.ViewModels
                 Bits[i].Color       = "#26C200";
                 Bits[i].Description = $"Bit {i}";
             }
+
+            OnPropertyChanged(nameof(ActiveCount));
         }
     }
 }