fix(ui): refresh GPU memory gauge periodically

tests/conditional/test_operator_ui.py

@@ -31,3 +31,72 @@ def test_gradio_application_constructs_without_public_listener():
     assert probe.returncode == 0, probe.stderr
     assert probe.stdout.strip() == "operator UI constructed without a listener"
     assert probe.stderr == ""
+
+
+def test_gpu_memory_refresh_controls_have_one_configurable_polling_loop():
+    """Exercise the rendered Gradio graph rather than relying on source shape."""
+    pytest.importorskip("gradio", reason="install the locked spaces extra")
+    probe = subprocess.run(
+        [
+            sys.executable,
+            "-c",
+            r'''
+import asyncio
+import app
+
+config = app.demo.get_config_file()
+components = config["components"]
+timers = [item for item in components if item["type"] == "timer"]
+assert len(timers) == 1
+timer = timers[0]
+assert timer["props"]["value"] == 30.0
+assert timer["props"]["active"] is True
+
+selectors = [
+    item for item in components
+    if "vram-refresh-control" in item["props"].get("elem_classes", [])
+]
+assert len(selectors) == 1
+selector = selectors[0]
+assert selector["type"] == "dropdown"
+assert selector["props"]["label"] == "GPU refresh"
+assert selector["props"]["choices"] == [
+    ("10 sec", 10.0), ("30 sec", 30.0), ("1 min", 60.0)
+]
+assert selector["props"]["value"] == 30.0
+assert selector["props"]["filterable"] is False
+assert selector["props"]["allow_custom_value"] is False
+assert selector["props"]["min_width"] == 96
+
+timer_ticks = [
+    dependency for dependency in config["dependencies"]
+    if (timer["id"], "tick") in dependency["targets"]
+]
+assert len(timer_ticks) == 1
+assert timer_ticks[0]["queue"] is False
+assert timer_ticks[0]["outputs"] == [app.vram_display._id]
+
+interval_changes = [
+    dependency for dependency in config["dependencies"]
+    if (selector["id"], "change") in dependency["targets"]
+    and dependency["outputs"] == [timer["id"]]
+]
+assert len(interval_changes) == 1
+assert interval_changes[0]["queue"] is False
+
+async def verify_interval_changes():
+    for seconds in (10.0, 30.0, 60.0):
+        result = await app.demo.process_api(
+            interval_changes[0]["id"], [seconds], state=None
+        )
+        assert result["data"] == [seconds]
+
+asyncio.run(verify_interval_changes())
+''',
+        ],
+        capture_output=True,
+        text=True,
+        timeout=120,
+        check=False,
+    )
+    assert probe.returncode == 0, probe.stdout + probe.stderr