fix(python): add async SimpleBox metrics

sdks/python/boxlite/simplebox.py

@@ -292,6 +292,15 @@ async def collect_stderr():
             error_message=error_message,
         )
 
+    async def metrics(self):
+        """Get box metrics (CPU, memory usage)."""
+        if not self._started:
+            raise RuntimeError(
+                "Box not started. Use 'async with SimpleBox(...) as box:' "
+                "or call 'await box.start()' first."
+            )
+        return await self._box.metrics()
+
     async def stop(self):
         """
         Stop the box and release resources.

sdks/python/tests/test_simplebox.py

@@ -0,0 +1,18 @@
+"""Integration tests for the async SimpleBox convenience wrapper."""
+
+from __future__ import annotations
+
+import pytest
+
+import boxlite
+
+pytestmark = [pytest.mark.integration, pytest.mark.asyncio]
+
+
+async def test_simplebox_metrics(shared_runtime):
+    """Async SimpleBox exposes box metrics like SyncSimpleBox."""
+    async with boxlite.SimpleBox(image="alpine:latest", runtime=shared_runtime) as box:
+        await box.exec("echo", "test")
+        metrics = await box.metrics()
+        assert metrics is not None
+        assert metrics.commands_executed_total >= 1