fix: address 2 quality review findings — begin_batch dirty guard, LIMIT<=0 warning

winnow/jobs.py

@@ -71,8 +71,8 @@ def _resolve_strategy(strategy: str, has_embedding: bool) -> tuple[int | str, st
     custom_limit = _getenv_optional_int("LIMIT")
     if custom_limit is not None and custom_limit > 0:
         return custom_limit, "smart"
-    if custom_limit == 0:
-        logger.warning("LIMIT=0 is invalid — ignoring and using auto strategy")
+    if custom_limit is not None and custom_limit <= 0:
+        logger.warning("LIMIT=%s is invalid — ignoring and using auto strategy", custom_limit)
 
     strategy_map = {
         "adaptive": ("auto", "smart"),

winnow/upload_tracker.py

@@ -105,7 +105,7 @@ def begin_batch(filename: str) -> None:
     """
     path = _tracker_path(filename)
     key = str(path)
-    if key in _deferred and key in _cache:
+    if key in _deferred and key in _dirty:
         try:
             _write_to_disk(path, _cache[key])
         except Exception: