feat(rsbuild): use selectable native compiler by default

Refs #686

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

Author: owjs3901

.changepacks/changepack_log_w74-native-engine.json

@@ -1,7 +1,8 @@
 {
   "changes": {
     "packages/plugin-utils/package.json": "Patch",
-    "packages/webpack-plugin/package.json": "Patch"
+    "packages/webpack-plugin/package.json": "Patch",
+    "packages/rsbuild-plugin/package.json": "Patch"
   },
   "note": "Add shared native/WASM compiler selection, structural compiler types and exact native platform-load diagnostics for build plugins.",
   "date": "2026-10-30T17:29:00.000Z"