docs(18-01): complete auto-take-ownership settings foundation plan

- 18-01-SUMMARY.md: plan execution summary
- STATE.md: progress updated to 98%, decisions recorded, stopped-at updated
- ROADMAP.md: phase 18 marked in-progress (1/2 summaries)
- REQUIREMENTS.md: OWN-01 marked complete

.planning/REQUIREMENTS.md

@@ -18,7 +18,7 @@ Requirements for v2.3 Tenant Management & Report Enhancements. Each maps to road
 
 ### Site Ownership
 
-- [ ] **OWN-01**: User can enable/disable auto-take-ownership in application settings (global toggle, OFF by default)
+- [x] **OWN-01**: User can enable/disable auto-take-ownership in application settings (global toggle, OFF by default)
 - [ ] **OWN-02**: App automatically takes site collection admin ownership when encountering access denied during scans (when toggle is ON)
 
 ### Report Enhancements
@@ -54,7 +54,7 @@ Requirements for v2.3 Tenant Management & Report Enhancements. Each maps to road
 | APPREG-04 | Phase 19 | Pending |
 | APPREG-05 | Phase 19 | Pending |
 | APPREG-06 | Phase 19 | Pending |
-| OWN-01 | Phase 18 | Pending |
+| OWN-01 | Phase 18 | Complete |
 | OWN-02 | Phase 18 | Pending |
 | RPT-01 | Phase 17 | Complete |
 | RPT-02 | Phase 17 | Complete |

.planning/ROADMAP.md

@@ -102,7 +102,7 @@ Plans:
   2. When the toggle is OFF, access-denied sites produce the same error behavior as before v2.3 (no regression)
   3. When the toggle is ON and a scan hits access denied on a site, the app automatically calls `Tenant.SetSiteAdmin` to elevate ownership and retries the site without interrupting the scan
   4. The scan result for an auto-elevated site is visually distinguishable from a normally-scanned site (e.g., a flag or icon in the results)
-**Plans:** 2 plans
+**Plans:** 1/2 plans executed
 Plans:
 - [ ] 18-01-PLAN.md — Settings toggle + OwnershipElevationService + PermissionEntry.WasAutoElevated flag
 - [ ] 18-02-PLAN.md — Scan-loop elevation logic + DataGrid visual differentiation
@@ -129,5 +129,5 @@ Plans:
 | 15. Consolidation Data Model | v2.3 | 2/2 | Complete | 2026-04-09 |
 | 16. Report Consolidation Toggle | v2.3 | 2/2 | Complete | 2026-04-09 |
 | 17. Group Expansion in HTML Reports | 2/2 | Complete    | 2026-04-09 | — |
-| 18. Auto-Take Ownership | v2.3 | 0/2 | Planned | — |
+| 18. Auto-Take Ownership | 1/2 | In Progress|  | — |
 | 19. App Registration & Removal | v2.3 | 0/? | Not started | — |

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v2.3
 milestone_name: Tenant Management & Report Enhancements
 status: planning
-stopped_at: Completed 17-02-PLAN.md
-last_updated: "2026-04-09T11:13:35.417Z"
+stopped_at: Completed 18-01-PLAN.md
+last_updated: "2026-04-09T12:25:36.302Z"
 last_activity: 2026-04-09 — Roadmap created for v2.3 (phases 15-19)
 progress:
   total_phases: 5
   completed_phases: 3
-  total_plans: 6
-  completed_plans: 6
+  total_plans: 8
+  completed_plans: 7
 ---
 
 # Project State
@@ -71,6 +71,9 @@ Decisions are logged in PROJECT.md Key Decisions table.
 - [Phase 17]: Static helpers IsAadGroup/ExtractAadGroupId/StripClaims declared internal to enable unit testing via InternalsVisibleTo without polluting public API
 - [Phase 17]: Graph client created lazily on first AAD group encountered to avoid unnecessary auth overhead for groups with no nested AAD members
 - [Phase 17]: groupMembers optional param in HtmlExportService — null produces identical pre-Phase-17 output; ISharePointGroupResolver injected as optional last param in PermissionsViewModel; resolution failure degrades gracefully with LogWarning
+- [Phase 18-auto-take-ownership]: OwnershipElevationService uses Tenant.SetSiteAdmin from PnP.Framework
+- [Phase 18-auto-take-ownership]: WasAutoElevated last positional param with default=false preserves all existing PermissionEntry callsites
+- [Phase 18-auto-take-ownership]: AutoTakeOwnership ViewModel setter uses fire-and-forget pattern matching DataFolder
 
 ### Pending Todos
 
@@ -82,7 +85,7 @@ None.
 
 ## Session Continuity
 
-Last session: 2026-04-09T11:11:03.823Z
-Stopped at: Completed 17-02-PLAN.md
+Last session: 2026-04-09T12:25:29.455Z
+Stopped at: Completed 18-01-PLAN.md
 Resume file: None
 Next step: `/gsd:plan-phase 15`

.planning/phases/18-auto-take-ownership/18-01-SUMMARY.md

@@ -0,0 +1,83 @@
+---
+phase: 18-auto-take-ownership
+plan: "01"
+subsystem: settings, models, services
+tags: [auto-take-ownership, settings, permission-entry, elevation-service, di]
+dependency_graph:
+  requires: []
+  provides: [AppSettings.AutoTakeOwnership, PermissionEntry.WasAutoElevated, IOwnershipElevationService, OwnershipElevationService, SettingsViewModel.AutoTakeOwnership]
+  affects: [SharepointToolbox/Core/Models/AppSettings.cs, SharepointToolbox/Core/Models/PermissionEntry.cs, SharepointToolbox/Services/SettingsService.cs, SharepointToolbox/ViewModels/Tabs/SettingsViewModel.cs, SharepointToolbox/Views/Tabs/SettingsView.xaml]
+tech_stack:
+  added: [IOwnershipElevationService, OwnershipElevationService, Microsoft.Online.SharePoint.TenantAdministration.Tenant.SetSiteAdmin]
+  patterns: [fire-and-forget property setter pattern (matching DataFolder), DI transient registration]
+key_files:
+  created:
+    - SharepointToolbox/Services/IOwnershipElevationService.cs
+    - SharepointToolbox/Services/OwnershipElevationService.cs
+    - SharepointToolbox.Tests/Services/OwnershipElevationServiceTests.cs
+    - SharepointToolbox.Tests/ViewModels/SettingsViewModelOwnershipTests.cs
+  modified:
+    - SharepointToolbox/Core/Models/AppSettings.cs
+    - SharepointToolbox/Core/Models/PermissionEntry.cs
+    - SharepointToolbox/Services/SettingsService.cs
+    - SharepointToolbox/ViewModels/Tabs/SettingsViewModel.cs
+    - SharepointToolbox/Views/Tabs/SettingsView.xaml
+    - SharepointToolbox/Localization/Strings.resx
+    - SharepointToolbox/Localization/Strings.fr.resx
+    - SharepointToolbox/App.xaml.cs
+decisions:
+  - "OwnershipElevationService.ElevateAsync uses Tenant.SetSiteAdmin from PnP.Framework (Microsoft.Online.SharePoint.TenantAdministration)"
+  - "WasAutoElevated placed last with default=false in PermissionEntry positional record to avoid breaking all existing callsites"
+  - "AutoTakeOwnership in SettingsViewModel follows fire-and-forget pattern matching DataFolder setter"
+metrics:
+  duration: "~15 minutes"
+  tasks_completed: 2
+  files_modified: 8
+  files_created: 4
+  completed_date: "2026-04-09"
+---
+
+# Phase 18 Plan 01: Auto-Take Ownership Settings Foundation Summary
+
+**One-liner:** AppSettings, PermissionEntry, IOwnershipElevationService/impl, and SettingsView checkbox for auto-take-ownership toggle backed by full EN/FR localization and 10 new tests.
+
+## Tasks Completed
+
+| Task | Name | Commit | Files |
+|------|------|--------|-------|
+| 1 | Models + SettingsService + OwnershipElevationService + tests | 36fb312 | AppSettings.cs, PermissionEntry.cs, SettingsService.cs, IOwnershipElevationService.cs, OwnershipElevationService.cs, SettingsViewModel.cs, App.xaml.cs, 2 test files |
+| 2 | SettingsView XAML + localization | 20948e4 | SettingsView.xaml, Strings.resx, Strings.fr.resx |
+
+## What Was Built
+
+- `AppSettings.AutoTakeOwnership` bool property defaulting to `false`, round-trips through JSON.
+- `PermissionEntry.WasAutoElevated` optional positional parameter (last, default `false`) — zero callsite breakage.
+- `SettingsService.SetAutoTakeOwnershipAsync(bool)` persists toggle following same pattern as `SetLanguageAsync`/`SetDataFolderAsync`.
+- `IOwnershipElevationService` interface with `ElevateAsync(ClientContext, siteUrl, loginName, ct)`.
+- `OwnershipElevationService` wraps `Tenant.SetSiteAdmin` from PnP.Framework.
+- DI registration: `services.AddTransient<IOwnershipElevationService, OwnershipElevationService>()` in App.xaml.cs.
+- `SettingsViewModel.AutoTakeOwnership` property loads from settings on `LoadAsync()`, persists on set via fire-and-forget `SetAutoTakeOwnershipAsync`.
+- `SettingsView.xaml` "Site Ownership" section with `CheckBox` bound to `AutoTakeOwnership`, with description `TextBlock`.
+- EN/FR localization keys: `settings.ownership.title`, `settings.ownership.auto`, `settings.ownership.description`.
+- 10 new tests covering all behaviors; full suite: 328 passed, 28 skipped, 0 failed.
+
+## Decisions Made
+
+1. `OwnershipElevationService.ElevateAsync` uses `Tenant.SetSiteAdmin` (already available via PnP.Framework `Microsoft.Online.SharePoint.TenantAdministration`).
+2. `WasAutoElevated` placed last with `= false` default in the positional record — no existing callsite needed updating.
+3. `AutoTakeOwnership` ViewModel setter uses `_ = _settingsService.SetAutoTakeOwnershipAsync(value)` matching the `DataFolder` fire-and-forget pattern.
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Test Results
+
+- `dotnet build SharepointToolbox.slnx` — 0 errors, 0 warnings
+- `dotnet test ... --filter OwnershipElevation|SettingsViewModelOwnership` — 8/8 passed
+- `dotnet test ... --filter LocaleCompleteness` — 2/2 passed
+- Full suite — 328 passed, 0 failed, 28 skipped
+
+## Self-Check: PASSED
+
+All created files exist. All commits verified. Full test suite green.