改善 Studio 回放布局与传感器切换体验

缩短界面提示，保存上次视频目录，并防止旧结果绘入 Finger 3D。针对性测试及可见界面复测通过。

apps/studio/config/locales/en_US.json

@@ -209,13 +209,13 @@
     "view_mode_tip": "Image display mode while running",
     "replay_pipeline": "Recorded video (raw camera image)",
     "replay_pipeline_tip": "Replay shows the recorded raw camera image with no live arrow overlay; to get arrows and depth from analysis, use View → Analyze video",
-    "replay_raw_note": "A recording stores only the raw camera image: there is no flow or depth to draw, because this recording has no analysis result yet. Opening a recording runs the pass automatically, or press “Analyze video”; once a result exists this pane can draw arrows and the depth map",
+    "replay_raw_note": "No analysis result yet. Opening a recording runs analysis, or choose Analyze video… above.",
     "frame_missing_note": "This frame carries no {fields}: there is nothing for this view to draw",
     "field_flow": "flow",
     "field_depth": "depth",
     "recompute_pipeline": "Recomputed from the recording (not the recorded value)",
     "recompute_pipeline_tip": "This frame is what the current algorithm version computes for that footage — not the measurement that was recorded at the time.",
-    "replay_empty": "No recording open\nPress “Open recording…” below",
+    "replay_empty": "No video open\nChoose “Recorded video…” above",
     "arrow_empty": "No image yet\nPick a video or camera, then press Run",
     "arrow_empty_tip": "The deformation arrow image appears here while running or previewing",
     "arrow_render_failed": "Flow arrows could not be drawn for this frame\nTry another view, or reload the video",
@@ -244,7 +244,7 @@
     "mesh3d_reset_tip": "Reset view: back to the framing the scene itself uses",
     "replay_analysis_running": "this recording is being analysed: there are no arrows or depth to draw until it finishes. Progress and Cancel are on the analysis panel.",
     "replay_analysis_failed": "there is no analysis result to draw: {reason}. Only the raw camera image can be shown here; once that is dealt with, Analyze video runs the pass again by hand.",
-    "replay_analysis_unavailable": "this is not a recording that can be analysed (its folder has no session.json, or no raw_*.mp4 segment): no pass can run, so this panel shows the raw camera image only. For forces and deformation from this video use View > Analyze video."
+    "replay_analysis_unavailable": "This video has no analysis setup. Choose Analyze video… above to select one and generate results."
   },
   "chart": {
     "fn": "FN",
@@ -295,7 +295,7 @@
     "no_video": "This recording has no usable video segment",
     "open_failed": "Could not open that recording: {error}",
     "not_a_recording": "“{name}” is not a recording: its folder has no forces.csv (a recording is the video plus forces.csv and session.json). Replay needs a recording; to just watch this video, open it as a video or use View ▸ Analyze video.",
-    "video_only_opened": "“{name}” has no recording beside it (no forces.csv), so it is playing as a video: the picture and the timeline work, the force charts are empty. For forces and deformation use View ▸ Analyze video.",
+    "video_only_opened": "Opened “{name}”; no analysis result yet. Choose Analyze video… above to generate one.",
     "video_only_notice": "This video has no recording beside it (no forces.csv): it plays, but the force charts and the recording details are empty.",
     "video_only_panel": "This is not a recording, and this video cannot be decoded (no forces.csv beside it, and it does not read as playable video)\nYou can still try View ▸ Analyze video",
     "empty_recording": "This recording has no playable picture (no raw_*.mp4 segment), so it cannot be replayed",
@@ -449,8 +449,9 @@
     "phase_connecting": "Connecting",
     "phase_running": "Acquiring",
     "phase_error": "Error",
-    "rail_video_name": "Video file: {name}",
-    "rail_result_profile": "Result profile: {type}",
+    "rail_video_name": "Video: {name}",
+    "rail_recent_video": "Previous video: {name}",
+    "rail_result_profile": "Result: {type}",
     "rail_result_reused": "Stored result",
     "rail_result_complete": "Analysis complete",
     "rail_result_running": "Analysing…",