fix(tui): address code review findings for multi-tab architecture

- Remove global EnvironmentChanged subscription from SqlQueryScreen (I-2)
- Make service caching thread-safe with Lazy<T> in InteractiveSession (I-1)
- Consolidate dual activation path: NavigateTo delegates to OnActiveTabChanged (I-3)
- Add Alt+1-9 hotkeys for direct tab selection (M-4)
- Assert spinner state transitions in SplashView tests (M-6)

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

Author: joshsmithxrm

src/PPDS.Cli/Tui/InteractiveSession.cs

@@ -45,13 +45,13 @@ internal sealed class InteractiveSession : IAsyncDisposable
     private string? _activeEnvironmentUrl;
     private string? _activeEnvironmentDisplayName;
     private bool _disposed;
-    private ITuiErrorService? _errorService;
-    private IHotkeyRegistry? _hotkeyRegistry;
-    private IProfileService? _profileService;
-    private IEnvironmentService? _environmentService;
-    private ITuiThemeService? _themeService;
-    private IQueryHistoryService? _queryHistoryService;
-    private IExportService? _exportService;
+    private readonly Lazy<ITuiErrorService> _errorService;
+    private readonly Lazy<IHotkeyRegistry> _hotkeyRegistry;
+    private readonly Lazy<IProfileService> _profileService;
+    private readonly Lazy<IEnvironmentService> _environmentService;
+    private readonly Lazy<ITuiThemeService> _themeService;
+    private readonly Lazy<IQueryHistoryService> _queryHistoryService;
+    private readonly Lazy<IExportService> _exportService;
 
     /// <summary>
     /// Event raised when the environment changes (either via initialization or explicit switch).
@@ -104,6 +104,15 @@ public InteractiveSession(
         _serviceProviderFactory = serviceProviderFactory ?? new ProfileBasedServiceProviderFactory();
         _deviceCodeCallback = deviceCodeCallback;
         _beforeInteractiveAuth = beforeInteractiveAuth;
+
+        // Initialize lazy service instances (thread-safe by default)
+        _profileService = new Lazy<IProfileService>(() => new ProfileService(_profileStore, NullLogger<ProfileService>.Instance));
+        _environmentService = new Lazy<IEnvironmentService>(() => new EnvironmentService(_profileStore, NullLogger<EnvironmentService>.Instance));
+        _themeService = new Lazy<ITuiThemeService>(() => new TuiThemeService());
+        _errorService = new Lazy<ITuiErrorService>(() => new TuiErrorService());
+        _hotkeyRegistry = new Lazy<IHotkeyRegistry>(() => new HotkeyRegistry());
+        _queryHistoryService = new Lazy<IQueryHistoryService>(() => new QueryHistoryService(NullLogger<QueryHistoryService>.Instance));
+        _exportService = new Lazy<IExportService>(() => new ExportService(NullLogger<ExportService>.Instance));
     }
 
     /// <summary>
@@ -452,7 +461,7 @@ await profileService.SetEnvironmentAsync(profileName, environmentUrl, environmen
     /// <returns>The profile service.</returns>
     public IProfileService GetProfileService()
     {
-        return _profileService ??= new ProfileService(_profileStore, NullLogger<ProfileService>.Instance);
+        return _profileService.Value;
     }
 
     /// <summary>
@@ -462,7 +471,7 @@ public IProfileService GetProfileService()
     /// <returns>The environment service.</returns>
     public IEnvironmentService GetEnvironmentService()
     {
-        return _environmentService ??= new EnvironmentService(_profileStore, NullLogger<EnvironmentService>.Instance);
+        return _environmentService.Value;
     }
 
     /// <summary>
@@ -481,7 +490,7 @@ public ProfileStore GetProfileStore()
     /// <returns>The theme service.</returns>
     public ITuiThemeService GetThemeService()
     {
-        return _themeService ??= new TuiThemeService();
+        return _themeService.Value;
     }
 
     /// <summary>
@@ -491,7 +500,7 @@ public ITuiThemeService GetThemeService()
     /// <returns>The error service.</returns>
     public ITuiErrorService GetErrorService()
     {
-        return _errorService ??= new TuiErrorService();
+        return _errorService.Value;
     }
 
     /// <summary>
@@ -501,7 +510,7 @@ public ITuiErrorService GetErrorService()
     /// <returns>The hotkey registry.</returns>
     public IHotkeyRegistry GetHotkeyRegistry()
     {
-        return _hotkeyRegistry ??= new HotkeyRegistry();
+        return _hotkeyRegistry.Value;
     }
 
     /// <summary>
@@ -511,7 +520,7 @@ public IHotkeyRegistry GetHotkeyRegistry()
     /// <returns>The query history service.</returns>
     public IQueryHistoryService GetQueryHistoryService()
     {
-        return _queryHistoryService ??= new QueryHistoryService(NullLogger<QueryHistoryService>.Instance);
+        return _queryHistoryService.Value;
     }
 
     /// <summary>
@@ -521,7 +530,7 @@ public IQueryHistoryService GetQueryHistoryService()
     /// <returns>The export service.</returns>
     public IExportService GetExportService()
     {
-        return _exportService ??= new ExportService(NullLogger<ExportService>.Instance);
+        return _exportService.Value;
     }
 
     #endregion

src/PPDS.Cli/Tui/Screens/SqlQueryScreen.cs

@@ -250,9 +250,6 @@ public SqlQueryScreen(Action<DeviceCodeInfo>? deviceCodeCallback, InteractiveSes
             _resultsTable.Title = "Results";
         };
 
-        // Subscribe to environment changes from the session
-        Session.EnvironmentChanged += OnEnvironmentChanged;
-
         // Initialize results table with environment URL (already set by base constructor)
         if (EnvironmentUrl != null)
         {
@@ -324,28 +321,6 @@ private void SetupKeyboardHandling()
         };
     }
 
-    private void OnEnvironmentChanged(string? url, string? displayName)
-    {
-        Application.MainLoop?.Invoke(() =>
-        {
-            if (url != null)
-            {
-                EnvironmentUrl = url;
-                _resultsTable.SetEnvironmentUrl(EnvironmentUrl);
-
-                // Clear stale results from previous environment
-                _resultsTable.ClearData();
-                _lastSql = null;
-                _lastPagingCookie = null;
-                _lastPageNumber = 1;
-            }
-            else
-            {
-                EnvironmentUrl = null;
-            }
-        });
-    }
-
     private async Task ExecuteQueryAsync()
     {
         var sql = _queryInput.Text.ToString() ?? string.Empty;
@@ -782,6 +757,5 @@ public SqlQueryScreenState CaptureState()
 
     protected override void OnDispose()
     {
-        Session.EnvironmentChanged -= OnEnvironmentChanged;
     }
 }

src/PPDS.Cli/Tui/TuiShell.cs

@@ -100,40 +100,18 @@ public TuiShell(string? profileName, Action<DeviceCodeInfo>? deviceCodeCallback,
 
     /// <summary>
     /// Opens a screen in a new tab and makes it active.
+    /// Activation is handled by <see cref="OnActiveTabChanged"/> via the TabManager event.
     /// </summary>
     public void NavigateTo(ITuiScreen screen)
     {
         // Clear splash/main menu if still showing
         ClearSplashAndMainMenu();
 
-        // Deactivate current screen (if any)
-        if (_currentScreen != null)
-        {
-            _currentScreen.CloseRequested -= OnScreenCloseRequested;
-            _currentScreen.MenuStateChanged -= OnScreenMenuStateChanged;
-            _currentScreen.OnDeactivating();
-            _contentArea.Remove(_currentScreen.Content);
-        }
-
-        // Add screen as a new tab
+        // Add screen as a new tab — AddTab fires ActiveTabChanged,
+        // which calls OnActiveTabChanged to handle activation.
         var envUrl = (screen as TuiScreenBase)?.EnvironmentUrl ?? _session.CurrentEnvironmentUrl;
         var envName = _session.CurrentEnvironmentDisplayName;
         _tabManager.AddTab(screen, envUrl, envName);
-
-        // Activate the new screen
-        _currentScreen = screen;
-        _currentScreen.CloseRequested += OnScreenCloseRequested;
-        _currentScreen.MenuStateChanged += OnScreenMenuStateChanged;
-        _hotkeyRegistry.SetActiveScreen(screen);
-        _contentArea.Title = screen.Title;
-        _contentArea.Add(screen.Content);
-        screen.OnActivated(_hotkeyRegistry);
-
-        // Rebuild menu bar with screen-specific items
-        RebuildMenuBar();
-
-        // Set focus to content
-        screen.Content.SetFocus();
     }
 
     private void OnScreenCloseRequested()
@@ -174,10 +152,6 @@ private void OnActiveTabChanged()
     {
         var activeTab = _tabManager.ActiveTab;
 
-        // Skip if already showing the correct screen (NavigateTo already activated it)
-        if (activeTab != null && _currentScreen == activeTab.Screen)
-            return;
-
         // Deactivate current screen if any
         if (_currentScreen != null)
         {
@@ -451,6 +425,17 @@ private void RegisterGlobalHotkeys()
             HotkeyScope.Global,
             "Previous tab",
             () => _tabManager.ActivatePrevious()));
+
+        // Direct tab selection: Alt+1 through Alt+9
+        for (var i = 0; i < 9; i++)
+        {
+            var index = i;
+            _hotkeyRegistrations.Add(_hotkeyRegistry.Register(
+                Key.AltMask | (Key)('1' + i),
+                HotkeyScope.Global,
+                $"Tab {i + 1}",
+                () => _tabManager.ActivateTab(index)));
+        }
     }
 
     private void NavigateToSqlQuery()

tests/PPDS.Cli.Tests/Tui/Views/SplashViewTests.cs

@@ -13,6 +13,7 @@ public void InitialState_ShowsConnecting()
         var state = splash.CaptureState();
 
         Assert.False(state.IsReady);
+        Assert.True(state.SpinnerActive);
         Assert.NotNull(state.Version);
         Assert.NotEmpty(state.StatusMessage);
     }
@@ -38,6 +39,7 @@ public void SetReady_MarksReady()
         var state = splash.CaptureState();
 
         Assert.True(state.IsReady);
+        Assert.False(state.SpinnerActive);
     }
 
     [Fact]