refactor(auth): 🔨 relocate attribute declarations in BackgroundRefresher

Positioned the instance variable initializations earlier in the constructor to establish clear variable declarations at the outset of the method. This adjustment enhances code predictability by ensuring all attributes are defined before any complex logic execution.

Author: Mirrowel

src/rotator_library/background_refresher.py

@@ -18,6 +18,9 @@ class BackgroundRefresher:
     """
 
     def __init__(self, client: "RotatingClient"):
+        self._client = client
+        self._task: Optional[asyncio.Task] = None
+        self._initialized = False
         try:
             interval_str = os.getenv("OAUTH_REFRESH_INTERVAL", "600")
             self._interval = int(interval_str)
@@ -26,9 +29,6 @@ def __init__(self, client: "RotatingClient"):
                 f"Invalid OAUTH_REFRESH_INTERVAL '{interval_str}'. Falling back to 600s."
             )
             self._interval = 600
-        self._client = client
-        self._task: Optional[asyncio.Task] = None
-        self._initialized = False
 
     def start(self):
         """Starts the background refresh task."""