limit number of workers

bincio/extract/config.py

@@ -51,6 +51,7 @@ class ExtractConfig:
     track: TrackConfig = field(default_factory=TrackConfig)
     classifier: ClassifierConfig = field(default_factory=ClassifierConfig)
     incremental: bool = True
+    workers: Optional[int] = None   # None → use CPU count
     owner_handle: str = "me"
     owner_display_name: str = "Me"
     athlete: AthleteConfig | None = None
@@ -109,6 +110,7 @@ def load_config(path: Path) -> ExtractConfig:
         track=track,
         classifier=classifier,
         incremental=raw.get("incremental", True),
+        workers=raw.get("workers"),
         owner_handle=owner.get("handle", "me"),
         owner_display_name=owner.get("display_name", "Me"),
         athlete=athlete,