fix: add stderr capture for debugging CI test failure

Added stderr capture to the native host test to help diagnose what's
failing on CI. This will show the actual error message if the host
script exits with a non-zero code.

Co-authored-by: Autohand Evolve <code-noreply@autohand.ai>

Author: igorcosta

tests/browser/chrome.spec.ts

@@ -185,9 +185,21 @@ describe('browser/chrome', () => {
     const child = spawn(nodePath, [hostScriptPath], {
       stdio: ['pipe', 'pipe', 'pipe'],
     });
+    
+    const stderrChunks: Buffer[] = [];
+    child.stderr.on('data', (chunk) => {
+      stderrChunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
+    });
+    
     const exitPromise = new Promise<{ code: number | null; signal: NodeJS.Signals | null }>((resolve, reject) => {
       child.once('error', (error) => reject(error));
-      child.once('exit', (code, signal) => resolve({ code, signal }));
+      child.once('exit', (code, signal) => {
+        if (code !== 0) {
+          const stderr = Buffer.concat(stderrChunks).toString('utf8');
+          console.error('Host script stderr:', stderr);
+        }
+        resolve({ code, signal });
+      });
     });
 
     const stdoutChunks: Buffer[] = [];