分析结果在缺少会话零点时保留原始力值并说明原因

多点标定未测零点时，分析把整帧判无效，原始值与牛顿值都显示"不可用"；现按 SDK 标定模型约定只清空该轴牛顿值，并在回放提示与分析设置中说明需要零点。算法版本升为 flow-hhd-contact-2，旧缓存不再复用；新增测试在旧代码上失败、新代码通过，studio/shared 全量与 HEAD 失败集合一致。

apps/studio/config/locales/en_US.json

@@ -1,6 +1,7 @@
 {
   "multical": {
     "video_zero": "I confirm 30 frames from the reference frame are unloaded",
+    "video_zero_needed": "The chosen calibration is a multi-point model and needs a session zero. Without the box above, the result has raw values only, no newtons.",
     "video_zero_tip": "For models requiring a session zero. Measure it from this interval; tracker reference alone does not imply zero load.",
     "zero": "Unloaded zero",
     "zero_confirm": "Remove all load and keep the sensor unloaded for the next 30 processed frames. For video, pause at a known unloaded interval first. Measure a new session zero now?",
@@ -518,6 +519,7 @@
     "video_required": "Select a video file first",
     "config_missing": "Sensor config not found for {type}",
     "units_raw_fallback": "No usable calibration; showing raw for now",
+    "units_zero_missing": "This analysis measured no session zero, so only raw values exist: re-run it with “I confirm 30 frames from the reference frame are unloaded” checked",
     "reveal_failed": "Could not reveal config: {error}"
   },
   "scene3d": {

apps/studio/config/locales/zh_CN.json

@@ -1,6 +1,7 @@
 {
   "multical": {
     "video_zero": "我确认从参考帧开始的 30 帧均无载荷",
+    "video_zero_needed": "所选标定是多点模型，需要会话零点。不勾选上面一项，分析结果只有原始值，没有牛顿值。",
     "video_zero_tip": "适用于需要单独测量零点的模型。用此片段测量会话零点；选择跟踪参考帧本身不代表零载荷。",
     "zero": "无载荷置零",
     "zero_confirm": "请移除全部载荷，并在接下来 30 个处理帧内保持无载荷。使用录像时，请先暂停在已确认的无载荷片段。现在测量本次会话零点吗？",
@@ -518,6 +519,7 @@
     "video_required": "请先选择视频文件",
     "config_missing": "未找到传感器配置: {type}",
     "units_raw_fallback": "无可用标定，暂显示原始单位",
+    "units_zero_missing": "这次分析没有测零点，只能显示原始值：请在分析设置中勾选「我确认从参考帧开始的 30 帧均无载荷」后重新分析",
     "reveal_failed": "无法打开配置位置: {error}"
   },
   "scene3d": {