feat(15-01): add LocationInfo and ConsolidatedPermissionEntry model records

- LocationInfo record holds five location fields (SiteUrl, SiteTitle, ObjectTitle, ObjectUrl, ObjectType)
- ConsolidatedPermissionEntry record holds key fields plus IReadOnlyList<LocationInfo> Locations
- LocationCount computed property returns Locations.Count

SharepointToolbox/Core/Models/ConsolidatedPermissionEntry.cs

@@ -0,0 +1,21 @@
+namespace SharepointToolbox.Core.Models;
+
+/// <summary>
+/// A consolidated permission row produced by grouping UserAccessEntry rows
+/// that share the same (UserLogin, PermissionLevel, AccessType, GrantedThrough) key.
+/// All distinct locations for that key are collected into <see cref="Locations"/>.
+/// </summary>
+public record ConsolidatedPermissionEntry(
+    string UserDisplayName,
+    string UserLogin,
+    string PermissionLevel,
+    AccessType AccessType,
+    string GrantedThrough,
+    bool IsHighPrivilege,
+    bool IsExternalUser,
+    IReadOnlyList<LocationInfo> Locations
+)
+{
+    /// <summary>Convenience count — equals Locations.Count.</summary>
+    public int LocationCount => Locations.Count;
+}

SharepointToolbox/Core/Models/LocationInfo.cs

@@ -0,0 +1,13 @@
+namespace SharepointToolbox.Core.Models;
+
+/// <summary>
+/// Holds the five location-related fields extracted from a UserAccessEntry
+/// when permission rows are merged into a consolidated entry.
+/// </summary>
+public record LocationInfo(
+    string SiteUrl,
+    string SiteTitle,
+    string ObjectTitle,
+    string ObjectUrl,
+    string ObjectType
+);