fix(e2e): resolve vite binary from node_modules instead of npx

npx may not find vite in CI. Resolve the binary directly from the
example app's or monorepo root's node_modules/.bin instead.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: piotrski

packages/e2e-tests/src/vite-server.ts

@@ -6,6 +6,21 @@ const VITE_APP_DIR = path.resolve(
   '../../../examples/vite-app',
 );
 
+/**
+ * Resolve the vite binary from the example app's node_modules.
+ * Falls back to the monorepo root's node_modules.
+ */
+function getViteBin(): string {
+  const localBin = path.join(VITE_APP_DIR, 'node_modules', '.bin', 'vite');
+  const rootBin = path.resolve(VITE_APP_DIR, '../../node_modules/.bin/vite');
+  try {
+    require('fs').accessSync(localBin);
+    return localBin;
+  } catch {
+    return rootBin;
+  }
+}
+
 /**
  * Start a Vite dev server for the example app with a custom devtools port.
  * Uses AGENT_DEVTOOLS_PORT env var read by the example app's vite config.
@@ -14,25 +29,30 @@ export async function startViteServer(
   vitePort: number,
   daemonPort: number,
 ): Promise<ChildProcess> {
+  const viteBin = getViteBin();
   const viteProcess = spawn(
-    'npx',
-    ['vite', '--port', String(vitePort), '--strictPort'],
+    viteBin,
+    ['--port', String(vitePort), '--strictPort'],
     {
       cwd: VITE_APP_DIR,
       env: { ...process.env, AGENT_DEVTOOLS_PORT: String(daemonPort) },
       stdio: 'pipe',
     },
   );
 
-  // Capture stderr for debugging if Vite fails
+  // Capture output for debugging if Vite fails
+  let stdoutOutput = '';
   let stderrOutput = '';
+  viteProcess.stdout?.on('data', (chunk: Buffer) => {
+    stdoutOutput += chunk.toString();
+  });
   viteProcess.stderr?.on('data', (chunk: Buffer) => {
     stderrOutput += chunk.toString();
   });
 
   await new Promise<void>((resolve, reject) => {
     const timeout = setTimeout(() => {
-      reject(new Error(`Vite failed to start within 30s. stderr:\n${stderrOutput}`));
+      reject(new Error(`Vite failed to start within 30s. stdout:\n${stdoutOutput}\nstderr:\n${stderrOutput}`));
     }, 30_000);
 
     const onOutput = (chunk: Buffer) => {