Fix Elasticsearch namespace filter exact match

Author: VijayabaskarR-06

server/src/main/java/org/eclipse/openvsx/search/ElasticSearchService.java

@@ -303,7 +303,7 @@ private ObjectBuilder<BoolQuery> createSearchQuery(BoolQuery.Builder boolQuery,
 
         if (!StringUtils.isEmpty(options.namespace())) {
             // Filter by namespace
-            boolQuery.must(QueryBuilders.term(builder -> builder.field("namespace").value(options.namespace()).caseInsensitive(true)));
+            boolQuery.must(QueryBuilders.term(builder -> builder.field("namespace.keyword").value(options.namespace()).caseInsensitive(true)));
         }
         if (!StringUtils.isEmpty(options.category())) {
             // Filter by selected category

server/src/test/java/org/eclipse/openvsx/search/ElasticSearchNamespaceFilterIT.java

@@ -0,0 +1,36 @@
+@Test
+void namespaceFilterMatchesOnlyExactNamespace() {
+
+    Extension vscode = new Extension();
+    vscode.setNamespace("vscode");
+    vscode.setName("python");
+    repositoryService.save(vscode);
+
+    Extension msVscode = new Extension();
+    msVscode.setNamespace("ms-vscode");
+    msVscode.setName("cpptools");
+    repositoryService.save(msVscode);
+
+    // Rebuild the index so both extensions are searchable
+    elasticSearchService.updateSearchIndex(true);
+
+    // Search using an exact namespace filter
+    Options options = new Options(
+            null,
+            "vscode",
+            null,
+            null,
+            null,
+            0,
+            10,
+            "desc",
+            SortBy.RELEVANCE
+    );
+
+    SearchResult result = elasticSearchService.search(options);
+
+    assertThat(result.extensions())
+            .extracting(ExtensionSearch::getNamespace)
+            .contains("vscode")
+            .doesNotContain("ms-vscode");
+}