Fix Withings via_device race causing flaky test_devices (#169347)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

homeassistant/components/withings/__init__.py

@@ -44,6 +44,7 @@ from homeassistant.const import (
 )
 from homeassistant.core import CALLBACK_TYPE, HomeAssistant
 from homeassistant.exceptions import ConfigEntryNotReady
+from homeassistant.helpers import device_registry as dr
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
 from homeassistant.helpers.config_entry_oauth2_flow import (
     ImplementationUnavailableError,
@@ -152,6 +153,12 @@ async def async_setup_entry(hass: HomeAssistant, entry: WithingsConfigEntry) ->
     for coordinator in withings_data.coordinators:
         await coordinator.async_config_entry_first_refresh()
 
+    device_registry = dr.async_get(hass)
+    device_registry.async_get_or_create(
+        config_entry_id=entry.entry_id,
+        identifiers={(DOMAIN, str(entry.unique_id))},
+        manufacturer="Withings",
+    )
     entry.runtime_data = withings_data
 
     webhook_manager = WithingsWebhookManager(hass, entry)

homeassistant/components/withings/entity.py

@@ -31,7 +31,6 @@ class WithingsEntity[_T: WithingsDataUpdateCoordinator[Any]](CoordinatorEntity[_
         self._attr_unique_id = f"withings_{coordinator.config_entry.unique_id}_{key}"
         self._attr_device_info = DeviceInfo(
             identifiers={(DOMAIN, str(coordinator.config_entry.unique_id))},
-            manufacturer="Withings",
         )