调整 Autocal 标定记录格式与目录命名

将人工参考载荷按档位区间保存，重排帧字段并明确界面操作。已通过相关测试、代码和文档检查。

apps/autocal/config/locales/zh_CN.json

@@ -263,6 +263,7 @@
     "frame": "帧 {frame} · 源帧 {source_frame} · {basis} {time} · 丢帧 {dropped}"
   },
   "calibration": {
+    "sensor_model": "产品型号",
     "sensor_sn": "传感器 SN",
     "output": "保存目录",
     "site_view": "选择测点",
@@ -272,13 +273,15 @@
     "levels": "加载档位 (N)",
     "hold": "建议保持",
     "reference": "实际参考力 (N)",
-    "start": "开始记录",
-    "confirm": "确认到档",
-    "finish": "结束试验",
+    "start": "开始试验并录制",
+    "confirm": "确认当前档位",
+    "finish": "完成并保存",
     "abort": "中止并保留",
     "load": "加载",
     "unload": "卸载",
     "next_step": "下一档：{branch}至 {load:g} N",
+    "before_start": "请先开始试验并录制",
+    "ready_to_finish": "全部档位已确认，请完成并保存",
     "no_step": "无待确认档位",
     "progress": "进度 {done}/{total} · {status}",
     "held": " · 当前档已保持 {seconds:.1f} s",