minor #792 Add example error output to runner output (chr-hertel)

This PR was merged into the main branch.

Discussion
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 Add example error output to runner output

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Docs?         | no
| Issues        |
| License       | MIT

Before:
<img width="1273" height="873" alt="image" src="https://github.com/user-attachments/assets/cf7f09e5-b5c6-4657-9687-a1cf498bb821" />

After:
<img width="1646" height="948" alt="image" src="https://github.com/user-attachments/assets/74288f19-2728-41e7-b884-240b4bd5d45e" />

Commits
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2bdb9a9 Add example error output to runner output

Author: chr-hertel

examples/runner

@@ -119,7 +119,8 @@ $app = (new SingleCommandApplication('Symfony AI Example Runner'))
         foreach ($exampleRuns as $run) {
             if (!$run['process']->isSuccessful()) {
                 $io->section('Error in ' . $run['example']->getRelativePathname());
-                $io->text($run['process']->getOutput());
+                $output = $run['process']->getErrorOutput();
+                $io->text('' !== $output ? $output : $run['process']->getOutput());
             }
         }