Treat 404 as auth error and persist refreshed tokens

The DKN Cloud NA API returns 404 (not 401) when tokens are expired,
which caused the integration to silently fail with UpdateFailed
indefinitely instead of attempting a token refresh or triggering
reauth. Refreshed tokens were also only held in memory, so they
were lost on Home Assistant restart.

- Add 404 to auth_error_statuses on is_logged_in, refresh_access_token,
  and fetch_installations.
- Persist refreshed access + refresh tokens back to the config entry
  after each successful coordinator update.
- Skip the entry reload listener for token-only option updates to
  avoid a reload loop on every refresh.
- Log API 4xx responses at WARNING with the body so failures are
  visible in HA logs without enabling debug logging.

custom_components/dkncloudna/api.py

@@ -90,7 +90,7 @@ class DknCloudNaClient:
                 "GET",
                 API_IS_LOGGED_IN,
                 require_auth=True,
-                auth_error_statuses={401, 403},
+                auth_error_statuses={401, 403, 404},
             )
         except DknAuthError:
             return False
@@ -106,7 +106,7 @@ class DknCloudNaClient:
             "GET",
             API_REFRESH_TOKEN.format(refresh_token=self.refresh_token),
             require_auth=bool(self.token),
-            auth_error_statuses={400, 401, 403},
+            auth_error_statuses={400, 401, 403, 404},
         )
         self._store_tokens(data)
 
@@ -117,7 +117,7 @@ class DknCloudNaClient:
             API_INSTALLATIONS,
             require_auth=True,
             retry_on_auth=True,
-            auth_error_statuses={401, 403},
+            auth_error_statuses={401, 403, 404},
         )
         if not isinstance(data, list):
             raise DknConnectionError("Unexpected installations response")
@@ -397,10 +397,20 @@ class DknCloudNaClient:
         except ClientError as err:
             raise DknConnectionError(str(err) or type(err).__name__) from err
 
-        LOGGER.debug("DKN response %s %s status=%s", method, url, response.status)
+        if response.status >= 400:
+            LOGGER.warning(
+                "DKN API error %s %s status=%s body=%s",
+                method,
+                url,
+                response.status,
+                data if not isinstance(data, str) or len(data) < 200 else data[:200],
+            )
+        else:
+            LOGGER.debug("DKN response %s %s status=%s", method, url, response.status)
 
         if response.status in (auth_error_statuses or set()):
             if retry_on_auth and self.refresh_token:
+                LOGGER.info("DKN token expired, attempting refresh")
                 await self.refresh_access_token()
                 return await self._request(
                     method,