feat(18-02): scan-loop elevation logic + PermissionsViewModel wiring + tests

- Add _settingsService and _ownershipService fields to PermissionsViewModel
- Add SettingsService? and IOwnershipElevationService? to both constructors
- Add DeriveAdminUrl internal static helper for admin URL derivation
- Add IsAccessDenied helper catching ServerUnauthorizedAccessException + WebException 403
- Add IsAutoTakeOwnershipEnabled async helper reading toggle from SettingsService
- Refactor RunOperationAsync with try/catch elevation pattern (read toggle before loop)
- Tag elevated entries with WasAutoElevated=true via record with expression
- Add PermissionsViewModelOwnershipTests (8 tests): toggle OFF propagates, toggle ON elevates+retries, no elevation on success, WasAutoElevated tagging, elevation throw propagates, DeriveAdminUrl theory

SharepointToolbox.Tests/ViewModels/PermissionsViewModelOwnershipTests.cs

@@ -0,0 +1,280 @@
+using System.Collections.Generic;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+using CommunityToolkit.Mvvm.Messaging;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.SharePoint.Client;
+using Moq;
+using SharepointToolbox.Core.Messages;
+using SharepointToolbox.Core.Models;
+using SharepointToolbox.Services;
+using SharepointToolbox.ViewModels;
+using SharepointToolbox.ViewModels.Tabs;
+
+namespace SharepointToolbox.Tests.ViewModels;
+
+/// <summary>
+/// Tests for auto-elevation logic in PermissionsViewModel scan loop.
+/// OWN-02: catch access-denied, call ElevateAsync, retry scan, tag entries.
+/// </summary>
+public class PermissionsViewModelOwnershipTests
+{
+    /// <summary>
+    /// Creates a ServerUnauthorizedAccessException via Activator (the reference assembly
+    /// exposes a different ctor signature than the runtime DLL — use runtime reflection).
+    /// </summary>
+    private static ServerUnauthorizedAccessException MakeAccessDeniedException()
+    {
+        var t = typeof(ServerUnauthorizedAccessException);
+        var ctor = t.GetConstructors(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)[0];
+        return (ServerUnauthorizedAccessException)ctor.Invoke(new object?[] { "Access Denied", "", 0, "", "ServerUnauthorizedAccessException", null, "" });
+    }
+
+    private static readonly string SiteUrl = "https://tenant.sharepoint.com/sites/test";
+    private static readonly string TenantUrl = "https://tenant.sharepoint.com";
+
+    private static PermissionsViewModel CreateVm(
+        Mock<IPermissionsService> permissionsSvc,
+        Mock<ISessionManager> sessionManager,
+        SettingsService? settingsService = null,
+        IOwnershipElevationService? ownershipService = null)
+    {
+        var siteListSvc = new Mock<ISiteListService>();
+        var logger = NullLogger<FeatureViewModelBase>.Instance;
+
+        var vm = new PermissionsViewModel(
+            permissionsSvc.Object,
+            siteListSvc.Object,
+            sessionManager.Object,
+            logger,
+            settingsService: settingsService,
+            ownershipService: ownershipService);
+
+        WeakReferenceMessenger.Default.Send(new GlobalSitesChangedMessage(
+            new List<SiteInfo> { new(SiteUrl, "Test Site") }.AsReadOnly()));
+        vm.SetCurrentProfile(new TenantProfile
+        {
+            Name = "Test",
+            TenantUrl = TenantUrl,
+            ClientId = "client-id"
+        });
+
+        return vm;
+    }
+
+    /// <summary>
+    /// When AutoTakeOwnership=false and ScanSiteAsync throws ServerUnauthorizedAccessException,
+    /// the exception propagates.
+    /// </summary>
+    [Fact]
+    public async Task ScanLoop_ToggleOff_AccessDenied_ExceptionPropagates()
+    {
+        var permSvc = new Mock<IPermissionsService>();
+        permSvc
+            .Setup(s => s.ScanSiteAsync(It.IsAny<ClientContext>(), It.IsAny<ScanOptions>(),
+                It.IsAny<IProgress<OperationProgress>>(), It.IsAny<CancellationToken>()))
+            .ThrowsAsync(MakeAccessDeniedException());
+
+        var sessionMgr = new Mock<ISessionManager>();
+        sessionMgr
+            .Setup(s => s.GetOrCreateContextAsync(It.IsAny<TenantProfile>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync((ClientContext)null!);
+
+        // No settingsService => toggle OFF (null treated as false)
+        var vm = CreateVm(permSvc, sessionMgr, settingsService: null, ownershipService: null);
+
+        await Assert.ThrowsAsync<ServerUnauthorizedAccessException>(
+            () => vm.TestRunOperationAsync(CancellationToken.None, new Progress<OperationProgress>()));
+    }
+
+    /// <summary>
+    /// When AutoTakeOwnership=true and scan throws access denied,
+    /// ElevateAsync is called once then ScanSiteAsync is retried.
+    /// </summary>
+    [Fact]
+    public async Task ScanLoop_ToggleOn_AccessDenied_ElevatesAndRetries()
+    {
+        var permSvc = new Mock<IPermissionsService>();
+        var callCount = 0;
+        permSvc
+            .Setup(s => s.ScanSiteAsync(It.IsAny<ClientContext>(), It.IsAny<ScanOptions>(),
+                It.IsAny<IProgress<OperationProgress>>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(() =>
+            {
+                callCount++;
+                if (callCount == 1)
+                    throw MakeAccessDeniedException();
+                return new List<PermissionEntry>
+                {
+                    new("Site", "Test", SiteUrl, true, "User1", "u1@t.com", "Full Control", "Direct", "User")
+                };
+            });
+
+        var sessionMgr = new Mock<ISessionManager>();
+        sessionMgr
+            .Setup(s => s.GetOrCreateContextAsync(It.IsAny<TenantProfile>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync((ClientContext)null!);
+
+        var elevationSvc = new Mock<IOwnershipElevationService>();
+        elevationSvc
+            .Setup(e => e.ElevateAsync(It.IsAny<ClientContext>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .Returns(Task.CompletedTask);
+
+        var settingsSvc = FakeSettingsServiceWithAutoOwnership(true);
+
+        var vm = CreateVm(permSvc, sessionMgr, settingsService: settingsSvc, ownershipService: elevationSvc.Object);
+
+        await vm.TestRunOperationAsync(CancellationToken.None, new Progress<OperationProgress>());
+
+        // ElevateAsync called once
+        elevationSvc.Verify(
+            e => e.ElevateAsync(It.IsAny<ClientContext>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()),
+            Times.Once);
+
+        // ScanSiteAsync called twice (first fails, retry succeeds)
+        permSvc.Verify(
+            s => s.ScanSiteAsync(It.IsAny<ClientContext>(), It.IsAny<ScanOptions>(),
+                It.IsAny<IProgress<OperationProgress>>(), It.IsAny<CancellationToken>()),
+            Times.Exactly(2));
+    }
+
+    /// <summary>
+    /// When ScanSiteAsync succeeds on first try, ElevateAsync is never called.
+    /// </summary>
+    [Fact]
+    public async Task ScanLoop_ScanSucceeds_ElevateNeverCalled()
+    {
+        var permSvc = new Mock<IPermissionsService>();
+        permSvc
+            .Setup(s => s.ScanSiteAsync(It.IsAny<ClientContext>(), It.IsAny<ScanOptions>(),
+                It.IsAny<IProgress<OperationProgress>>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new List<PermissionEntry>
+            {
+                new("Site", "Test", SiteUrl, true, "User1", "u1@t.com", "Full Control", "Direct", "User")
+            });
+
+        var sessionMgr = new Mock<ISessionManager>();
+        sessionMgr
+            .Setup(s => s.GetOrCreateContextAsync(It.IsAny<TenantProfile>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync((ClientContext)null!);
+
+        var elevationSvc = new Mock<IOwnershipElevationService>();
+        var settingsSvc = FakeSettingsServiceWithAutoOwnership(true);
+
+        var vm = CreateVm(permSvc, sessionMgr, settingsService: settingsSvc, ownershipService: elevationSvc.Object);
+
+        await vm.TestRunOperationAsync(CancellationToken.None, new Progress<OperationProgress>());
+
+        elevationSvc.Verify(
+            e => e.ElevateAsync(It.IsAny<ClientContext>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()),
+            Times.Never);
+    }
+
+    /// <summary>
+    /// After successful elevation+retry, returned entries have WasAutoElevated=true.
+    /// </summary>
+    [Fact]
+    public async Task ScanLoop_AfterElevation_EntriesTaggedWasAutoElevated()
+    {
+        var permSvc = new Mock<IPermissionsService>();
+        var callCount = 0;
+        permSvc
+            .Setup(s => s.ScanSiteAsync(It.IsAny<ClientContext>(), It.IsAny<ScanOptions>(),
+                It.IsAny<IProgress<OperationProgress>>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(() =>
+            {
+                callCount++;
+                if (callCount == 1)
+                    throw MakeAccessDeniedException();
+                return new List<PermissionEntry>
+                {
+                    new("Site", "Test", SiteUrl, true, "User1", "u1@t.com", "Full Control", "Direct", "User")
+                };
+            });
+
+        var sessionMgr = new Mock<ISessionManager>();
+        sessionMgr
+            .Setup(s => s.GetOrCreateContextAsync(It.IsAny<TenantProfile>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync((ClientContext)null!);
+
+        var elevationSvc = new Mock<IOwnershipElevationService>();
+        elevationSvc
+            .Setup(e => e.ElevateAsync(It.IsAny<ClientContext>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .Returns(Task.CompletedTask);
+
+        var settingsSvc = FakeSettingsServiceWithAutoOwnership(true);
+
+        var vm = CreateVm(permSvc, sessionMgr, settingsService: settingsSvc, ownershipService: elevationSvc.Object);
+
+        await vm.TestRunOperationAsync(CancellationToken.None, new Progress<OperationProgress>());
+
+        Assert.NotEmpty(vm.Results);
+        Assert.All(vm.Results, e => Assert.True(e.WasAutoElevated));
+    }
+
+    /// <summary>
+    /// If ElevateAsync itself throws, the exception propagates (no infinite retry).
+    /// </summary>
+    [Fact]
+    public async Task ScanLoop_ElevationThrows_ExceptionPropagates()
+    {
+        var permSvc = new Mock<IPermissionsService>();
+        permSvc
+            .Setup(s => s.ScanSiteAsync(It.IsAny<ClientContext>(), It.IsAny<ScanOptions>(),
+                It.IsAny<IProgress<OperationProgress>>(), It.IsAny<CancellationToken>()))
+            .ThrowsAsync(MakeAccessDeniedException());
+
+        var sessionMgr = new Mock<ISessionManager>();
+        sessionMgr
+            .Setup(s => s.GetOrCreateContextAsync(It.IsAny<TenantProfile>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync((ClientContext)null!);
+
+        var elevationSvc = new Mock<IOwnershipElevationService>();
+        elevationSvc
+            .Setup(e => e.ElevateAsync(It.IsAny<ClientContext>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ThrowsAsync(new InvalidOperationException("Elevation failed"));
+        // ScanSiteAsync always throws access denied (does NOT succeed after elevation throws)
+
+
+        var settingsSvc = FakeSettingsServiceWithAutoOwnership(true);
+
+        var vm = CreateVm(permSvc, sessionMgr, settingsService: settingsSvc, ownershipService: elevationSvc.Object);
+
+        await Assert.ThrowsAsync<InvalidOperationException>(
+            () => vm.TestRunOperationAsync(CancellationToken.None, new Progress<OperationProgress>()));
+
+        // ScanSiteAsync was called exactly once (no retry after elevation failure)
+        permSvc.Verify(
+            s => s.ScanSiteAsync(It.IsAny<ClientContext>(), It.IsAny<ScanOptions>(),
+                It.IsAny<IProgress<OperationProgress>>(), It.IsAny<CancellationToken>()),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Validates DeriveAdminUrl logic for standard tenant URL.
+    /// </summary>
+    [Theory]
+    [InlineData("https://tenant.sharepoint.com", "https://tenant-admin.sharepoint.com")]
+    [InlineData("https://tenant.sharepoint.com/", "https://tenant-admin.sharepoint.com")]
+    [InlineData("https://tenant-admin.sharepoint.com", "https://tenant-admin.sharepoint.com")]
+    public void DeriveAdminUrl_ReturnsCorrectAdminUrl(string input, string expected)
+    {
+        var result = PermissionsViewModel.DeriveAdminUrl(input);
+        Assert.Equal(expected, result);
+    }
+
+    // ── Helpers ───────────────────────────────────────────────────────────────
+
+    private static SettingsService FakeSettingsServiceWithAutoOwnership(bool enabled)
+    {
+        // Use in-memory temp file
+        var tempFile = System.IO.Path.GetTempFileName();
+        System.IO.File.Delete(tempFile);
+        var repo = new SharepointToolbox.Infrastructure.Persistence.SettingsRepository(tempFile);
+        var svc = new SettingsService(repo);
+        // Seed via SetAutoTakeOwnershipAsync synchronously
+        svc.SetAutoTakeOwnershipAsync(enabled).GetAwaiter().GetResult();
+        return svc;
+    }
+}

SharepointToolbox/ViewModels/Tabs/PermissionsViewModel.cs

@@ -29,6 +29,8 @@ public partial class PermissionsViewModel : FeatureViewModelBase
     private readonly IBrandingService? _brandingService;
     private readonly ISharePointGroupResolver? _groupResolver;
     private readonly ILogger<FeatureViewModelBase> _logger;
+    private readonly SettingsService? _settingsService;
+    private readonly IOwnershipElevationService? _ownershipService;
 
     // ── Observable properties ───────────────────────────────────────────────
 
@@ -136,7 +138,9 @@ public partial class PermissionsViewModel : FeatureViewModelBase
         HtmlExportService htmlExportService,
         IBrandingService brandingService,
         ILogger<FeatureViewModelBase> logger,
-        ISharePointGroupResolver? groupResolver = null)
+        ISharePointGroupResolver? groupResolver = null,
+        SettingsService? settingsService = null,
+        IOwnershipElevationService? ownershipService = null)
         : base(logger)
     {
         _permissionsService = permissionsService;
@@ -147,6 +151,8 @@ public partial class PermissionsViewModel : FeatureViewModelBase
         _brandingService = brandingService;
         _groupResolver = groupResolver;
         _logger = logger;
+        _settingsService = settingsService;
+        _ownershipService = ownershipService;
 
         ExportCsvCommand = new AsyncRelayCommand(ExportCsvAsync, CanExport);
         ExportHtmlCommand = new AsyncRelayCommand(ExportHtmlAsync, CanExport);
@@ -160,7 +166,9 @@ public partial class PermissionsViewModel : FeatureViewModelBase
         ISiteListService siteListService,
         ISessionManager sessionManager,
         ILogger<FeatureViewModelBase> logger,
-        IBrandingService? brandingService = null)
+        IBrandingService? brandingService = null,
+        SettingsService? settingsService = null,
+        IOwnershipElevationService? ownershipService = null)
         : base(logger)
     {
         _permissionsService = permissionsService;
@@ -170,6 +178,8 @@ public partial class PermissionsViewModel : FeatureViewModelBase
         _htmlExportService = null;
         _brandingService = brandingService;
         _logger = logger;
+        _settingsService = settingsService;
+        _ownershipService = ownershipService;
 
         ExportCsvCommand = new AsyncRelayCommand(ExportCsvAsync, CanExport);
         ExportHtmlCommand = new AsyncRelayCommand(ExportHtmlAsync, CanExport);
@@ -217,6 +227,9 @@ public partial class PermissionsViewModel : FeatureViewModelBase
             FolderDepth: FolderDepth,
             IncludeSubsites: IncludeSubsites);
 
+        // Read toggle once before the loop (avoids async in exception filter)
+        var autoOwnership = await IsAutoTakeOwnershipEnabled();
+
         int i = 0;
         foreach (var url in nonEmpty)
         {
@@ -230,9 +243,38 @@ public partial class PermissionsViewModel : FeatureViewModelBase
                 Name = _currentProfile?.Name ?? string.Empty
             };
 
-            var ctx = await _sessionManager.GetOrCreateContextAsync(profile, ct);
+            bool wasElevated = false;
-            var siteEntries = await _permissionsService.ScanSiteAsync(ctx, scanOptions, progress, ct);
+            IReadOnlyList<PermissionEntry> siteEntries;
-            allEntries.AddRange(siteEntries);
+
+            try
+            {
+                var ctx = await _sessionManager.GetOrCreateContextAsync(profile, ct);
+                siteEntries = await _permissionsService.ScanSiteAsync(ctx, scanOptions, progress, ct);
+            }
+            catch (Exception ex) when (IsAccessDenied(ex) && _ownershipService != null && autoOwnership)
+            {
+                _logger.LogWarning("Access denied on {Url}, auto-elevating ownership...", url);
+                var adminUrl = DeriveAdminUrl(_currentProfile?.TenantUrl ?? url);
+                var adminProfile = new TenantProfile
+                {
+                    TenantUrl = adminUrl,
+                    ClientId = _currentProfile?.ClientId ?? string.Empty,
+                    Name = _currentProfile?.Name ?? string.Empty
+                };
+                var adminCtx = await _sessionManager.GetOrCreateContextAsync(adminProfile, ct);
+                await _ownershipService.ElevateAsync(adminCtx, url, string.Empty, ct);
+
+                // Retry scan with fresh context
+                var retryCtx = await _sessionManager.GetOrCreateContextAsync(profile, ct);
+                siteEntries = await _permissionsService.ScanSiteAsync(retryCtx, scanOptions, progress, ct);
+                wasElevated = true;
+            }
+
+            if (wasElevated)
+                allEntries.AddRange(siteEntries.Select(e => e with { WasAutoElevated = true }));
+            else
+                allEntries.AddRange(siteEntries);
+
             i++;
         }
 
@@ -260,6 +302,38 @@ public partial class PermissionsViewModel : FeatureViewModelBase
         ExportHtmlCommand.NotifyCanExecuteChanged();
     }
 
+    // ── Auto-ownership helpers ───────────────────────────────────────────────
+
+    /// <summary>
+    /// Derives the tenant admin URL from a standard tenant URL.
+    /// E.g. https://tenant.sharepoint.com → https://tenant-admin.sharepoint.com
+    /// </summary>
+    internal static string DeriveAdminUrl(string tenantUrl)
+    {
+        var uri = new Uri(tenantUrl.TrimEnd('/'));
+        var host = uri.Host;
+        if (host.Contains("-admin.sharepoint.com", StringComparison.OrdinalIgnoreCase))
+            return tenantUrl;
+        var adminHost = host.Replace(".sharepoint.com", "-admin.sharepoint.com",
+            StringComparison.OrdinalIgnoreCase);
+        return $"{uri.Scheme}://{adminHost}";
+    }
+
+    private static bool IsAccessDenied(Exception ex)
+    {
+        if (ex is Microsoft.SharePoint.Client.ServerUnauthorizedAccessException) return true;
+        if (ex is System.Net.WebException webEx && webEx.Response is System.Net.HttpWebResponse resp
+            && resp.StatusCode == System.Net.HttpStatusCode.Forbidden) return true;
+        return false;
+    }
+
+    private async Task<bool> IsAutoTakeOwnershipEnabled()
+    {
+        if (_settingsService == null) return false;
+        var settings = await _settingsService.GetSettingsAsync();
+        return settings.AutoTakeOwnership;
+    }
+
     // ── Tenant switching ─────────────────────────────────────────────────────
 
     protected override void OnTenantSwitched(TenantProfile profile)