fix: honor IgnoreErrors in batch tasks

Element failures no longer cancel sibling elements or stop later groups.

core/tasks/batchtfile/execute.go

@@ -53,7 +53,11 @@ func (t *Task) Execute(ctx context.Context) error {
 			i = end
 		}
 		if err != nil {
-			break
+			if !t.IgnoreErrors {
+				break
+			}
+			logger.Warnf("Group processing failed (ignored): %v", err)
+			err = nil
 		}
 	}
 	if err != nil {
@@ -104,7 +108,14 @@ func (t *Task) processElements(ctx context.Context, elems []*TaskElement) error
 				return err
 			}
 			defer t.unmarkProcessing(elem.ID)
-			return t.processElement(gctx, *elem)
+			err := t.processElement(gctx, *elem)
+			if err != nil && t.IgnoreErrors {
+				// Element failure is already recorded per-item; keep siblings
+				// running by not propagating the error to the errgroup.
+				log.FromContext(ctx).Warnf("Element %s failed (ignored): %v", elem.ID, err)
+				return nil
+			}
+			return err
 		})
 	}
 	return eg.Wait()
@@ -127,7 +138,12 @@ func (t *Task) processBatch(ctx context.Context, group executionGroup) error {
 				return err
 			}
 			defer t.unmarkProcessing(elem.ID)
-			return t.downloadElement(gctx, elem)
+			err := t.downloadElement(gctx, elem)
+			if err != nil && t.IgnoreErrors {
+				log.FromContext(ctx).Warnf("Element %s failed (ignored): %v", elem.ID, err)
+				return nil
+			}
+			return err
 		})
 	}
 	if err := eg.Wait(); err != nil {

core/tasks/batchtfile/task.go

@@ -47,7 +47,6 @@ type Task struct {
 	uploadOnce      sync.Once
 	uploadMu        sync.Mutex
 	uploaded        map[string]int64
-	failed          map[string]error // [TODO] errors for each element
 }
 
 // Title implements core.Exectable.
@@ -136,7 +135,6 @@ func NewBatchTGFileTask(
 		uploaded:     make(map[string]int64),
 		IgnoreErrors: ignoreErrors,
 		processingMu: sync.RWMutex{},
-		failed:       make(map[string]error),
 	}
 	return task
 }