Method onStart

frontend/src/services/uploadService.ts:108–117

()

  }

  onStart() {
    this.callbacks.onStart.forEach((callback) => {
      try {
        callback();
      } catch (e) {
        console.error("Error in upload start callback:", e);
      }
    });
    this.callbacks.onStart.clear();
  }

  onEnd() {
    this.callbacks.onEnd.forEach((callback) => {