收紧绘图设置为两页，并把 FN 牛顿下限固定为 0。

手指 2D 方向改到 ArrowPanel 设置对话框；归零阈值不变。已用 display_prefs、finger_2d_orientation 与绘图对话框相关 smoke 测试验证。

apps/studio/config/locales/en_US.json

@@ -52,10 +52,12 @@
   },
   "dialog": {
     "plot_settings_title": "Plot settings",
+    "plot_tab_curves": "Curves",
+    "plot_tab_filters": "Filters",
     "plot_window": "Time window",
     "plot_window_tip": "Force plot time window (seconds)",
     "plot_fn_min": "FN min",
-    "plot_fn_min_tip": "Normal-force axis minimum (Newton mode). It may be negative: leaving room below zero keeps the idle curve off the FX frame and makes small presses visible",
+    "plot_fn_min_tip": "Normal-force axis minimum (Newton mode); fixed at 0",
     "plot_fn_max": "FN max",
     "plot_fn_max_tip": "Normal force axis max (Newton mode)",
     "plot_shear_max": "Shear max",
@@ -204,6 +206,7 @@
     "view_depth": "Depth map",
     "view_recorded": "Recorded image",
     "view_mode_tip": "Image display mode while running",
+    "arrow_settings_tip": "Finger 2D presentation (orientation; display only)",
     "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": "No analysis result yet. Opening a recording runs analysis, or choose Analyze video… above.",

apps/studio/config/locales/zh_CN.json

@@ -52,10 +52,12 @@
   },
   "dialog": {
     "plot_settings_title": "绘图设置",
+    "plot_tab_curves": "曲线",
+    "plot_tab_filters": "滤波",
     "plot_window": "时间窗口",
     "plot_window_tip": "力曲线时间窗口（秒）",
     "plot_fn_min": "FN 下限",
-    "plot_fn_min_tip": "法向力纵轴下限（牛顿模式）。可以是负数：留出零点以下的空间，静止曲线不会压在 FX 框线上，小压力也更清楚",
+    "plot_fn_min_tip": "法向力纵轴下限（牛顿模式）；固定为 0",
     "plot_fn_max": "FN 上限",
     "plot_fn_max_tip": "法向力纵轴上限（牛顿模式）",
     "plot_shear_max": "剪切上限",
@@ -204,6 +206,7 @@
     "view_depth": "深度图",
     "view_recorded": "原始图像",
     "view_mode_tip": "运行时的图像显示模式",
+    "arrow_settings_tip": "手指 2D 显示方向（只影响画面）",
     "replay_pipeline": "录制视频（原始相机图像）",
     "replay_pipeline_tip": "回放显示的是录制下来的原始相机图像，不含实时箭头叠加；要看分析得到的箭头与深度请用「视图 → 分析视频」",
     "replay_raw_note": "尚无分析结果。打开录像会自动分析，或点顶部「分析视频…」。",