feat: page-based navigation shell + Tests page wizard

Replace the monolithic MainWindow with a SelectedPage-driven shell
(Dashboard / Pump / Bench / Tests / Results / Settings). The Tests
page gets the Plan -> Preconditions -> Running -> Done wizard from
ui-structure.md \u00a74, backed by a 7-item precondition gate and
shared sub-views (PhaseCardView / TestSectionView / GraphicIndicatorView)
extracted from the now-deleted monolithic TestPanelView.

New VMs / views:
- Tests wizard: TestPreconditions, PhaseCard, GraphicIndicator,
  TestSection, TestPlan, TestRunning, TestDone
- Dashboard panels: DashboardConnection, DashboardReadings,
  DashboardAlarms, InterlockBanner, ResultHistory
- Pump / bench panels: PumpIdentificationPanel, PumpLiveData,
  UnlockPanel, BenchDriveControl, BenchReadings, RelayBank,
  TemperatureControl, DtcList, AuthGate
- Dialogs: generic ConfirmDialog, UserManageDialog, UserPromptDialog

Supporting changes:
- IsOilPumpOn exposed on MainViewModel for precondition evaluation
- RequiresAuth added to TestDefinition (XML round-trip)
- BipStatusDefinition + CompletedTestRun models
- ~35 new Test.* localization keys (en + es)
- Settings moved from modal dialog to full page
- Pause / Retry / Skip stubs in TestRunningView; full spec in
  docs/gap-test-running-controls.md for follow-up implementation
- docs/ui-structure.md captures the wizard design

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

ViewModels/RelayBankViewModel.cs

@@ -0,0 +1,40 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using HC_APTBS.Models;
+using HC_APTBS.Services;
+
+namespace HC_APTBS.ViewModels
+{
+    /// <summary>
+    /// ViewModel for a curated bank of auxiliary relay toggles on the Bench page.
+    /// Excludes relays driven by dedicated controls
+    /// (oil pump, direction, heater / cooler, counter).
+    /// </summary>
+    public sealed partial class RelayBankViewModel : ObservableObject
+    {
+        private readonly IBenchService _bench;
+
+        /// <summary>Solenoid power / pump keep-alive relay.</summary>
+        [ObservableProperty] private bool _isElectronicOn;
+
+        /// <summary>Panel flasher relay (status lamp blink).</summary>
+        [ObservableProperty] private bool _isFlasherOn;
+
+        /// <summary>4-pulse-per-revolution output signal relay.</summary>
+        [ObservableProperty] private bool _isPulse4SignalOn;
+
+        /// <param name="benchService">Bench service used to drive the relays.</param>
+        public RelayBankViewModel(IBenchService benchService)
+        {
+            _bench = benchService;
+        }
+
+        partial void OnIsElectronicOnChanged(bool value)
+            => _bench.SetRelay(RelayNames.Electronic, value);
+
+        partial void OnIsFlasherOnChanged(bool value)
+            => _bench.SetRelay(RelayNames.Flasher, value);
+
+        partial void OnIsPulse4SignalOnChanged(bool value)
+            => _bench.SetRelay(RelayNames.Pulse4Signal, value);
+    }
+}