test: fixture for exercising the PR reviewer automation

Temporary. Adds an unreferenced markdown file containing two small,
obviously-flawed snippets so the automation has something concrete to
comment on. Close and delete once the review has been posted.

REVIEWER_AUTOMATION_TEST.md

@@ -0,0 +1,19 @@
+# PR reviewer automation — test fixture
+
+Temporary file used to exercise the OpenHands PR review automation
+end to end. It is not referenced by any build, test, or runtime path.
+
+Delete this file and close the PR once the automation has posted a review.
+
+## Deliberate review bait
+
+```python
+def divide(numerator, denominator):
+    # no zero check
+    return numerator / denominator
+
+
+def read_config(path):
+    # file handle is never closed
+    return open(path).read()
+```