Add comprehensive vitest tests for Next.js adapter

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

packages/adapters/nextjs/package.json

@@ -5,7 +5,9 @@
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "scripts": {
-    "build": "tsup --config ../../../tsup.config.ts"
+    "build": "tsup --config ../../../tsup.config.ts",
+    "test": "vitest run",
+    "test:watch": "vitest"
   },
   "peerDependencies": {
     "@objectstack/runtime": "workspace:*",
@@ -18,6 +20,7 @@
     "next": "^15.0.8",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
-    "typescript": "^5.0.0"
+    "typescript": "^5.0.0",
+    "vitest": "^4.0.18"
   }
 }

packages/adapters/nextjs/src/__mocks__/runtime.ts

@@ -0,0 +1,4 @@
+// Stub for @objectstack/runtime - replaced by vi.mock in tests
+export const HttpDispatcher = class {};
+export type ObjectKernel = any;
+export type HttpDispatcherResult = any;