Add test.py with addition function

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

test.py

@@ -0,0 +1,8 @@
+def add(a, b):
+    """Return the sum of two numbers."""
+    return a + b
+
+if __name__ == "__main__":
+    # Example usage
+    result = add(3, 5)
+    print(f"3 + 5 = {result}")