feat(runtime-tests): integration test suite

21 test files covering components, composables, focus, lifecycle,
and scheduler through the public render() API.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/runtime-tests/tsconfig.json

@@ -0,0 +1,21 @@
+{
+  "compilerOptions": {
+    "target": "esnext",
+    "lib": ["es2023"],
+    "moduleDetection": "force",
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    "resolveJsonModule": true,
+    "types": ["node"],
+    "strict": true,
+    "noUnusedLocals": true,
+    "noEmit": true,
+    "allowImportingTsExtensions": true,
+    "esModuleInterop": true,
+    "isolatedModules": true,
+    "verbatimModuleSyntax": true,
+    "skipLibCheck": true,
+    "jsx": "preserve",
+    "jsxImportSource": "vue"
+  }
+}