fix(typert): close remote gateway review gaps

vitest.shared.ts

@@ -1,5 +1,42 @@
+import ts from 'typescript'
+
+const decoratorSyntax = /^\s*@[A-Za-z_$][\w$]*/m
+
 /**
  * Worker arguments that keep process-wide Web Storage from shadowing jsdom storage.
  * Node lists the positive spelling in `allowedNodeEnvironmentFlags` for this negatable flag.
  */
 export const vitestExecArgv = process.allowedNodeEnvironmentFlags.has('--webstorage') ? ['--no-webstorage'] : []
+
+/**
+ * Transform standard TypeScript decorators before Vite's default parser sees source files.
+ * @returns a pre-transform Vite plugin shared by source-mode test configurations.
+ */
+export function standardDecoratorPlugin() {
+  return {
+    name: 'dsh-standard-decorators',
+    enforce: 'pre' as const,
+    transform(code: string, id: string) {
+      const file = id.split('?', 1)[0]!
+      if (!/\.[cm]?tsx?$/.test(file) || !decoratorSyntax.test(code)) return
+      const result = ts.transpileModule(code, {
+        fileName: file,
+        compilerOptions: {
+          target: ts.ScriptTarget.ES2024,
+          module: ts.ModuleKind.ESNext,
+          jsx: file.endsWith('x') ? ts.JsxEmit.ReactJSX : undefined,
+          sourceMap: true,
+        },
+      })
+      return {
+        code: result.outputText
+          .replace(
+            /^(\s*)(__esDecorate\()/gmu,
+            '$1/* v8 ignore next -- compiler-synthetic decorator accessors have no source behavior */ $2',
+          )
+          .replace(/\n?\/\/# sourceMappingURL=.*$/u, '\n'),
+        map: result.sourceMapText,
+      }
+    },
+  }
+}