Add Visualization tab to simulate.

Also:
- Increased label width in mjUI tight theme spacing.
- Added `mjITEM_EDITFLOAT` for editing float values.
- Move mjUI numpad key codes to header file.
PiperOrigin-RevId: 535839953
Change-Id: Ibdc0a9a20be514caa5b487211212ed6f5b8a6ba9

test/xml/xml_native_writer_test.cc

@@ -1068,5 +1068,27 @@ TEST_F(XMLWriterTest, WriteReadCompare) {
   }
 }
 
+// ---------------- test CopyBack functionality (decompiler) ------------------
+using DecompilerTest = MujocoTest;
+TEST_F(XMLWriterTest, SavesStatitics) {
+  static constexpr char xml[] = R"(
+  <mujoco>
+    <statistic meansize="2" extent="3" center="4 5 6"/>
+  </mujoco>
+  )";
+  mjModel* model = LoadModelFromString(xml);
+  ASSERT_THAT(model, NotNull());
+  model->stat.meansize = 7;
+  model->stat.extent = 8;
+  model->stat.center[0] = 9;
+  model->stat.center[1] = 10;
+  model->stat.center[2] = 11;
+  std::string saved_xml = SaveAndReadXml(model);
+  EXPECT_THAT(saved_xml, HasSubstr("meansize=\"7\""));
+  EXPECT_THAT(saved_xml, HasSubstr("extent=\"8\""));
+  EXPECT_THAT(saved_xml, HasSubstr("center=\"9 10 11\""));
+  mj_deleteModel(model);
+}
+
 }  // namespace
 }  // namespace mujoco