admin: match official Decap demo nested config — subfolders:false, depth:100, index_file:index

app/src/web/admin/config.yml

@@ -29,11 +29,9 @@ collections:
     folder: subjects
     create: true
     slug: "{{slug}}"
-    # nested mode: shows subjects/<subject>/<slug>/ tree (Decap-native for subfolders)
-    nested:
-      depth: 2
-    meta:
-      path: { widget: string, label: Path, index_file: _index, editable_folder: false, searchable: false }
+    # nested mode — matches Decap's official demo (subfolders:false + index_file)
+    nested: { depth: 100, subfolders: false }
+    meta: { path: { widget: string, label: 'Path', index_file: 'index' } }
     sortable_fields: [date, title]
     fields:
       - { name: title, label: Title, widget: string }