cleanup tests (#422)

- fix deprecation warning running `pnpm vitest --run`
- remove platform demo app placeholder test

Author: irahopkinson

demos/platform/src/app/app.spec.tsx

@@ -25,6 +25,7 @@ export default defineConfig({
     environment: "jsdom",
     include: ["{src,tests}/**/*.{test,spec}.{js,mjs,cjs,ts,mts,cts,jsx,tsx}"],
     reporters: ["default"],
+    passWithNoTests: true,
     coverage: {
       reportsDirectory: "./test-output/vitest/coverage",
       provider: "v8" as const,

demos/platform/vite.config.mts

@@ -0,0 +1,10 @@
+/// <reference types='vitest' />
+import { defineConfig } from "vite";
+
+export default defineConfig({
+  test: {
+    // Prevent the root project from collecting tests; let per-project configs handle discovery.
+    include: [],
+    projects: ["**/vite.config.{mjs,js,ts,mts}", "**/vitest.config.{mjs,js,ts,mts}"],
+  },
+});