feat(nativegen)!: refactor to struct-based native wrappers

Major overhaul of native wrapper generation for ufbx and nvtt.
Replaces all hand-written and class-based wrappers with auto-generated partial struct wrappers that directly expose native API methods via pointers. Introduces a new JSON-driven configuration system using "remaps" and "actions" for flexible parameter/return mapping and method routing. Removes legacy config sections and helper classes, focusing solely on method wrappers. Updates all usages and tests to use the new pointer-based API. Cleans up obsolete code and ensures resource management is handled via struct Dispose methods. The result is a thinner, more direct, and maintainable interop layer.

BREAKING CHANGE: All managed wrapper classes and helpers are removed in favor of struct-based pointer wrappers. API usage and resource management patterns have changed.

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

@@ -0,0 +1,96 @@
+{
+  "libraryName": "nvtt",
+  "nativeNamespace": "Ghost.Nvtt",
+  "outputNamespace": "Ghost.Nvtt",
+  "nativeTypePrefix": "Nvtt",
+  "skipTypes": [
+    "NativeAnnotationAttribute",
+    "NativeTypeNameAttribute"
+  ],
+  "skipFunctions": [],
+
+  "remaps": [
+    {
+      // sbyte* parameters whose names match name/filename/path/prop patterns
+      // get remapped to ReadOnlySpan<byte>, with a fixed() wrapper and _len sibling consumed.
+      "src": "sbyte*",
+      "dst": "ReadOnlySpan<byte>",
+      "scope": [ "parameter" ],
+      "filter": [ ".*name", ".*filename", ".*path", ".*prop$" ],
+      "adapter": {
+        "convertBack": {
+          "wrapCall": "fixed (byte* p$arg = $arg) { $CALL }",
+          "passAs": "(sbyte*)p$arg"
+        }
+      }
+    }
+  ],
+
+  "actions": [
+    {
+      // Dispose pattern: void return + T* param + name matches .*Destroy<Struct> → IDisposable.Dispose on T
+      // Must come BEFORE the general INSTANCE_METHOD rule so it matches first.
+      "comment": "Dispose pattern: void return + T* param → Dispose method on T",
+      "filter": "EXTERN_API",
+      "conditions": [ "VOID_RETURN", "SELF_PTR", "NAME_CONDITION(.*Destroy$TBare)" ],
+      "targetType": "FIRST_PARAM_TYPE",
+      "apply": [
+        {
+          "type": "INSTANCE_METHOD",
+          "opts": {
+            "removeFirstParam": true,
+            "passAs": "($TSelf*)System.Runtime.CompilerServices.Unsafe.AsPointer(ref this)",
+            "name": {
+              "set": "Dispose"
+            }
+          }
+        },
+        {
+          "type": "INHERITANCE",
+          "opts": {
+            "baseType": [ "System.IDisposable" ]
+          }
+        }
+      ]
+    },
+    {
+      // Instance method: first param is T* of a known binding struct → method on T
+      "comment": "First param is T* of a known binding struct → instance method on T",
+      "filter": "EXTERN_API",
+      "conditions": [ "SELF_PTR" ],
+      "targetType": "FIRST_PARAM_TYPE",
+      "apply": {
+        "type": "INSTANCE_METHOD",
+        "opts": {
+          "removeFirstParam": true,
+          "passAs": "($TSelf*)System.Runtime.CompilerServices.Unsafe.AsPointer(ref this)",
+          // Change "nvttCreateSurface" to "Create"
+          "name": {
+            "remove": [
+              "PREFIX",
+              "NO_PREFIX($TSelf)" // NO_PREFIX(NvttSurface) will change "NvttSurface" to "Surface", the prefix is determined by the "nativeTypePrefix" field at the top level of this config
+            ]
+          }
+        }
+      }
+    },
+    {
+      // Static method: first param is NOT a known struct pointer, but return type is T* → static on T
+      "comment": "Return type is T* of a known binding struct → static method on T",
+      "filter": "EXTERN_API",
+      "conditions": [ "FIRST_PARAM_OTHER_TYPE", "RETURN_BINDING_TYPE" ],
+      "targetType": "RETURN_TYPE",
+      "apply": {
+        "type": "STATIC_METHOD",
+        "opts": {
+          "name": {
+            "remove": [
+              "PREFIX",
+              "NO_PREFIX($TSelf)"
+            ]
+          }
+        }
+      }
+    }
+  ]
+}