fix(workflows): null-safe FieldDiff compact constructor, zh-CN locale for approval notification

Author: yan-3005

openmetadata-service/src/main/java/org/openmetadata/service/governance/workflows/util/ChangePreviewUtils.java

@@ -48,6 +48,11 @@ public final class ChangePreviewUtils {
   private ChangePreviewUtils() {}
 
   public record FieldDiff(List<String> added, List<String> removed) {
+    public FieldDiff {
+      added = added != null ? added : List.of();
+      removed = removed != null ? removed : List.of();
+    }
+
     FieldDiff merge(FieldDiff next) {
       return new FieldDiff(
           union(minus(added, next.removed), minus(next.added, removed)),

openmetadata-service/src/test/java/org/openmetadata/service/governance/workflows/util/ChangePreviewUtilsTest.java

@@ -255,6 +255,32 @@ void parseChangeMap_validJson_roundTrips() {
     assertEquals(List.of("PII.None"), parsed.get("tags").removed());
   }
 
+  @Test
+  void parseChangeMap_missingRemovedField_defaultsToEmpty() {
+    String json = "{\"tags\":{\"added\":[\"PII.Sensitive\"]}}";
+    Map<String, FieldDiff> parsed = ChangePreviewUtils.parseChangeMap(json);
+
+    assertEquals(List.of("PII.Sensitive"), parsed.get("tags").added());
+    assertTrue(parsed.get("tags").removed().isEmpty());
+  }
+
+  @Test
+  void parseChangeMap_missingAddedField_defaultsToEmpty() {
+    String json = "{\"tags\":{\"removed\":[\"PII.None\"]}}";
+    Map<String, FieldDiff> parsed = ChangePreviewUtils.parseChangeMap(json);
+
+    assertTrue(parsed.get("tags").added().isEmpty());
+    assertEquals(List.of("PII.None"), parsed.get("tags").removed());
+  }
+
+  @Test
+  void fieldDiff_nullComponentsInConstructor_defaultToEmpty() {
+    FieldDiff diff = new FieldDiff(null, null);
+    assertTrue(diff.added().isEmpty());
+    assertTrue(diff.removed().isEmpty());
+    assertTrue(diff.isEmpty());
+  }
+
   // ---------------------------------------------------------------------------
   // hasNoChanges
   // ---------------------------------------------------------------------------

openmetadata-ui/src/main/resources/ui/src/locale/languages/zh-cn.json

@@ -3023,7 +3023,7 @@
     "remove-lineage-edge": "删除血缘连线",
     "rename-entity": "修改{{entity}}的名称和显示名",
     "request-approval-message": "批准请求",
-    "request-approval-notification": "Approval required for",
+    "request-approval-notification": "需要批准：",
     "request-description": "请求详细描述",
     "request-description-message": "请求描述",
     "request-tags-message": "请求标签",