Persist file categories on the index and classify archives and unknown types during idle maintenance.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/Explorer.Application.Tests/ReorganizePlannerTests.cs

@@ -132,6 +132,40 @@ public class ReorganizePlannerTests
         Assert.Null(fs.GetItem(@"C:\Pictures\photo.jpg"));
     }
 
+    [Fact]
+    public void Prefers_indexed_archive_contents_over_extension()
+    {
+        var fs = Tree()
+            .Dir(@"C:\Downloads")
+            .File(@"C:\Downloads\photos.zip", 4, T0)
+            .Dir(@"C:\Pictures")
+            .Dir(@"C:\Archive");
+
+        var indexed = new Dictionary<string, IndexEntry>(StringComparer.OrdinalIgnoreCase)
+        {
+            ["photos.zip"] = new IndexEntry
+            {
+                Name = "photos.zip",
+                NameNorm = "photos.zip",
+                PathRel = "photos.zip",
+                Category = FileCategory.Photos,
+                CategorySource = CategorySources.ArchiveContents,
+                CategoryReason = "Archive contents are mostly photos."
+            }
+        };
+        var plan = new ReorganizePlanner().Build(
+            @"C:\Downloads",
+            Map(),
+            fs,
+            _ => true,
+            _ => false,
+            now: T0,
+            pathExists: _ => false,
+            indexedByName: indexed);
+        Assert.Contains(plan.Operations, o => o.SourcePath.EndsWith("photos.zip") && o.DestinationPath == @"C:\Pictures\photos.zip");
+        Assert.DoesNotContain(plan.Operations, o => o.DestinationPath == @"C:\Archive\photos.zip");
+    }
+
     private static OperationPlan Build(
         IFileSystemEnumerator fs,
         Action<OrganizeDestinations>? configure = null,