Chore: use model version_index prop on frontend too

src-ui/src/app/components/document-detail/document-version-dropdown/document-version-dropdown.component.html

@@ -88,7 +88,7 @@
                     @if (version.version_label) {
                       {{ version.version_label }}
                     } @else {
-                      <span class="fst-italic"><ng-container i18n>Version</ng-container>&nbsp;{{ versions.length - $index }}&nbsp;<span class="text-muted small">(#{{ version.id }})</span></span>
+                      <span class="fst-italic"><ng-container i18n>Version</ng-container>&nbsp;{{ (version.version_index ?? 0) + 1 }}&nbsp;<span class="text-muted small">(#{{ version.id }})</span></span>
                     }
                   </span>
                 }

src-ui/src/app/data/document.ts

@@ -172,6 +172,7 @@ export interface Document extends ObjectWithPermissions {
 export interface DocumentVersionInfo {
   id: number
   added?: Date
+  version_index: number
   version_label?: string
   checksum?: string
   is_root: boolean

src/documents/serialisers.py

@@ -1049,6 +1049,7 @@ class DuplicateDocumentSummarySerializer(serializers.Serializer):
 class DocumentVersionInfoSerializer(serializers.Serializer):
     id = serializers.IntegerField()
     added = serializers.DateTimeField()
+    version_index = serializers.IntegerField()
     version_label = serializers.CharField(required=False, allow_null=True)
     checksum = serializers.CharField(required=False, allow_null=True)
     is_root = serializers.BooleanField()
@@ -1057,6 +1058,7 @@ class DocumentVersionInfoSerializer(serializers.Serializer):
 class _DocumentVersionInfo(TypedDict):
     id: int
     added: datetime
+    version_index: int
     version_label: str | None
     checksum: str | None
     is_root: bool
@@ -1140,6 +1142,7 @@ class DocumentSerializer(
                 "id",
                 "added",
                 "checksum",
+                "version_index",
                 "version_label",
             )
             versions = [*versions_qs, root_doc]
@@ -1148,6 +1151,7 @@ class DocumentSerializer(
             return {
                 "id": doc.id,
                 "added": doc.added,
+                "version_index": doc.version_index,
                 "version_label": doc.version_label,
                 "checksum": doc.checksum,
                 "is_root": doc.id == root_doc.id,