Add extract worker configuration controls

internal/core/config/effective_config.go

@@ -26,6 +26,7 @@ type EffectiveConfig struct {
 }
 
 func (c Config) Resolve(input ResolveInput) (EffectiveConfig, error) {
+	c.Concurrency.recomputeStageWorkerDefaults()
 	if err := c.Validate(); err != nil {
 		return EffectiveConfig{}, err
 	}