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/SharepointToolbox.csproj

@@ -8,6 +8,8 @@
     <UseWPF>true</UseWPF>
     <PublishTrimmed>false</PublishTrimmed>
     <StartupObject>SharepointToolbox.App</StartupObject>
+    <!-- LiveCharts2 transitive deps (SkiaSharp.Views.WPF, OpenTK) lack net10.0 targets but work at runtime -->
+    <NoWarn>$(NoWarn);NU1701</NoWarn>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(PublishSingleFile)' == 'true'">