fix persistent rate limits

rate_limiter.py

@@ -38,7 +38,7 @@ class RateLimitState:
             "daily_count": self.daily_count,
             "total_count": self.total_count,
             "last_access_time": self.last_access_time,
-            "last_access_date": str(self.last_access_date),
+            "last_access_date": self.last_access_date.strftime("%Y-%m-%d"),
         }
 
     @staticmethod
@@ -47,14 +47,15 @@ class RateLimitState:
         state.daily_count = data.get("daily_count", 0)
         state.total_count = data.get("total_count", 0)
         state.last_access_time = data.get("last_access_time")
-        state.last_access_date = datetime.datetime.strptime(
-            data.get("last_access_date"), "%Y-%m-%d"
-        ).date()
+        state.last_access_date = data.get("last_access_date").date()
         return state
+    
+    def __repr__(self):
+        return json.dumps(self.to_dict(), default=_json_dumper)
 
 
 class RateLimiter:
-    def __init__(self, config: RateLimitConfig, flush_interval=60):
+    def __init__(self, config: RateLimitConfig, flush_interval=30):
         """
         flush_interval = how often (seconds) to push logs to HF dataset
         """