chore: archive v1.1 Enhanced Reports milestone

v1.1 shipped with 4 phases (25 plans), 10/10 requirements complete:
- Global site selection (toolbar picker, all tabs consume)
- User access audit (Graph people-picker, direct/group/inherited)
- Simplified permissions (plain-language labels, risk levels, detail toggle)
- Storage visualization (LiveCharts2 pie/donut + bar charts)

Post-phase polish: centralized site selection (removed per-tab pickers),
claims prefix stripping, StorageMetrics backfill, chart tooltip fix,
summary stats in app + HTML exports.

205 tests passing, 10,484 LOC.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

SharepointToolbox.Tests/ViewModels/StorageViewModelChartTests.cs

@@ -122,13 +122,13 @@ public class StorageViewModelChartTests
         SetFileTypeMetrics(vm, metrics);
 
         // Initially IsDonutChart=true => InnerRadius=50
-        var pieBefore = vm.PieChartSeries.Cast<PieSeries<long>>().ToList();
+        var pieBefore = vm.PieChartSeries.Cast<PieSeries<double>>().ToList();
         Assert.All(pieBefore, s => Assert.Equal(50, s.InnerRadius));
 
         // Toggle to bar (not donut) => InnerRadius=0
         vm.IsDonutChart = false;
 
-        var pieAfter = vm.PieChartSeries.Cast<PieSeries<long>>().ToList();
+        var pieAfter = vm.PieChartSeries.Cast<PieSeries<double>>().ToList();
         Assert.All(pieAfter, s => Assert.Equal(0, s.InnerRadius));
     }