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/Dialogs/ConfirmDialogViewModel.cs

@@ -0,0 +1,51 @@
+using System;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+
+namespace HC_APTBS.ViewModels.Dialogs
+{
+    /// <summary>
+    /// Generic Yes/No (or Confirm/Cancel) modal dialog view-model.
+    ///
+    /// <para>Reusable across abort-test, skip-phase, delete-pump, and any future
+    /// binary decision prompt. Caller sets <see cref="Title"/>, <see cref="Message"/>,
+    /// <see cref="ConfirmText"/>, <see cref="CancelText"/> before showing the dialog,
+    /// then inspects <see cref="Accepted"/> after the dialog closes.</para>
+    /// </summary>
+    public sealed partial class ConfirmDialogViewModel : ObservableObject
+    {
+        /// <summary>Window title.</summary>
+        [ObservableProperty] private string _title = string.Empty;
+
+        /// <summary>Body message — may be multi-line.</summary>
+        [ObservableProperty] private string _message = string.Empty;
+
+        /// <summary>Text shown on the positive-action button (defaults to a localised "OK").</summary>
+        [ObservableProperty] private string _confirmText = "OK";
+
+        /// <summary>Text shown on the cancel button (defaults to a localised "Cancel").</summary>
+        [ObservableProperty] private string _cancelText = "Cancel";
+
+        /// <summary>True when the operator clicked <see cref="ConfirmText"/>; false on cancel/close.</summary>
+        public bool Accepted { get; private set; }
+
+        /// <summary>Raised when the dialog should close itself.</summary>
+        public event Action? RequestClose;
+
+        /// <summary>Accepts the prompt — sets <see cref="Accepted"/> to true and closes.</summary>
+        [RelayCommand]
+        private void Confirm()
+        {
+            Accepted = true;
+            RequestClose?.Invoke();
+        }
+
+        /// <summary>Cancels the prompt — leaves <see cref="Accepted"/> false and closes.</summary>
+        [RelayCommand]
+        private void Cancel()
+        {
+            Accepted = false;
+            RequestClose?.Invoke();
+        }
+    }
+}