test(db): add real-resource close test to restore coverage

Author: warku123

framework/src/test/java/org/tron/core/db/CheckPointV2StoreTest.java

@@ -41,6 +41,13 @@ public static void destroy() {
     Args.clearParam();
   }
 
+  @Test
+  public void testCloseWithRealResources() {
+    CheckPointV2Store store = new CheckPointV2Store("test-close-real");
+    // Exercises the real writeOptions.close() and dbSource.closeDB() code paths
+    store.close();
+  }
+
   @Test
   public void testCloseReleasesAllResources() throws Exception {
     CheckPointV2Store store = new CheckPointV2Store("test-close");