feat: update version badge logic for same-base update strategy, see #676

- Remove unused isNewer variable calculation
- Use dividerThresholdVersionId instead of latestLibraryVersionId for badge logic
- Add test case to verify newer version badge appears with same-base strategy
- Ensures correct badge display when filtering by same base model versions

static/js/components/shared/ModelVersionsTab.js

@@ -567,9 +567,6 @@ function render(record) {
 
     const rowsMarkup = filteredVersions
         .map(version => {
-            const isNewer =
-                typeof latestLibraryVersionId === 'number' &&
-                version.versionId > latestLibraryVersionId;
             let markup = '';
             if (
                 !dividerInserted &&
@@ -580,7 +577,7 @@ function render(record) {
                 markup += '<div class="version-divider" role="presentation"></div>';
             }
             markup += renderRow(version, {
-                latestLibraryVersionId,
+                latestLibraryVersionId: dividerThresholdVersionId,
                 currentVersionId: normalizedCurrentVersionId,
                 modelId: record?.modelId ?? modelId,
             });