feat(bindings): update C# wrappers for meshopt, nvtt, ufbx

Refactor and regenerate native C# bindings for Ghost.MeshOptimizer, Ghost.Nvtt, and Ghost.Ufbx to match updated native APIs and improve usability.
- Replace meshoptimizer.dll with newer version.
- Move meshoptimizer functions to static methods in partial class; add new meshlet, simplification, quantization features.
- Remove enum wrappers in favor of constants; delete meshopt_Allocator.cs.
- Regenerate native wrappers with PascalCase naming, XML doc comments, and aggressive inlining.
- Implement IDisposable for resource structs; update configs for naming, documentation, and method mapping.
- Update user code to use new wrapper classes and method names.
- Improve documentation and comments for clarity.

BREAKING CHANGE: API surface changes, wrapper class and method names updated, enum wrappers removed, custom allocator deleted.

src/Tools/Ghost.NativeWrapperGen/configs/nvtt.json

@@ -91,6 +91,20 @@
           }
         }
       }
+    },
+    {
+      "filter": "EXTERN_API",
+      "targetType": "NvttApi",
+      "apply": {
+        "type": "STATIC_METHOD",
+        "opts": {
+          "name": {
+            "remove": [
+              "PREFIX"
+            ]
+          }
+        }
+      }
     }
   ]
 }