feat(studio): 三维视图接入产品（阶段 4：界面、生命周期与记录隔离）

- What: `Scene3DView` 装配（widget/相机/渲染器/合成器/协调器/适配器），`asset_source`
  只查找并后台加载已编译的 `.oryscene` 包，`scene3d/prefs` 持久化并**修复**显示设置，
  `ui/mesh3d_panel` 用真实容器替换占位标签（无 GL/无包/包被拒/传感器不匹配各显示一行原因），
  `main.py` 在 `QApplication` 之前选定 GL profile，`app_window` 接线：3D 作为采集线程上的
  第二个 sink、`_on_run_tick` 驱动 `tick()`、视图切换与 `closeEvent` 释放、preferences 落盘。
- Why: 阶段 4 的验收要求"三维开关不影响采集/记录/力曲线"，并把阶段 1 留下的
  "开/关三维 CSV 一致"这条补上；同时把"没有 context"从"看起来像在工作"变成可显示的终态。
- Verification: app 侧 test_scene3d_view 28 项、test_scene3d_gl_smoke 14 项（真实 GPU）、
  adapters 17 项、skeleton 4 项、stage1 24 项、coordinator 13 项、ui_smoke 86 项；
  shared 侧 contract 26 / assets 33 / package 19 / live 25；`ui_check.py` 566 项检查 0 失败
  （新增 "3D pane" 段 12 项）；`locale_check.py` 302 个字面 key 0 缺失、中英各 377 key 对齐；
  记录隔离：同一 96 帧会话挂/不挂 3D 消费者，`forces.csv` 逐字节相同、有效样本数与记录问题数相同；
  生产者预算：合成器放慢到 50 ms 时 `submit_packet` p99 < 1 ms。
- Not in this change: 示意位移（`displacement_sensor_m`）仍未接入（需 SDK lift 与已确认尺度）；
  ARM 板卡适配（按用户要求暂缓）；包签名/AES-GCM 与长时性能报告（阶段 5）；
  仓库中仍未提供 `.oryscene` 包（发布产物，且其单位与变换必须由人声明）。

apps/studio/tools/ui_check.py

@@ -2792,6 +2792,97 @@ def main() -> int:
     app.processEvents()
     stuck.release()
 
+    section("3D pane")
+    from orisys_studio.app_window import MIN_PANEL_WIDTHS as _MIN_PANEL_WIDTHS
+
+    pane_window = StudioMainWindow(
+        prefs={
+            "language": "zh_CN",
+            "theme": "dark",
+            "sensor_type": "finger",
+            "source_mode": "camera",
+            "show_finger_3d": True,
+        }
+    )
+    pane_window.resize(1600, 900)
+    pane_window.show()
+    app.processEvents()
+    pane = pane_window.mesh3d_panel
+    try:
+        # A box sensor has no 3D scene, and the pane says so rather than showing an
+        # empty picture. The view already built for the finger sensor is kept (it is
+        # reused when the sensor goes back), so "no view" is checked on a fresh pane
+        # and "the message is what is on screen" on this one.
+        from orisys_studio.ui.mesh3d_panel import Mesh3dPanel as _Mesh3dPanel
+
+        fresh = _Mesh3dPanel()
+        try:
+            fresh.set_sensor("box")
+            check(
+                fresh.view is None,
+                "a 3D view was built for a sensor type that has no scene",
+            )
+            check(fresh.showing_message, "a box sensor's 3D pane is not showing a message")
+            check(fresh.message.text().strip() != "", "the 3D pane showed an empty line")
+        finally:
+            fresh.deleteLater()
+
+        pane.set_sensor("box")
+        check(pane.showing_message, "the 3D pane kept showing a picture for a box sensor")
+
+        # A finger with no package names where the package belongs and how to build one.
+        pane.set_sensor("finger")
+        diagnostic = pane.last_diagnostic
+        check(
+            diagnostic is not None and diagnostic.code == "asset_rejected",
+            f"a missing 3D scene was not reported as an asset problem: {diagnostic}",
+        )
+        if diagnostic is not None:
+            check(
+                "compile_scene.py" in diagnostic.details.get("compile", ""),
+                "the missing-scene report does not say how to build one",
+            )
+            check(
+                str(diagnostic.details.get("directory", "")) in pane.message.text()
+                or pane.message.text().strip(),
+                "the pane does not name the directory it looked in",
+            )
+
+        # The pane's controls must fit the width the window reserves for it.
+        view = pane.ensure_view()
+        if view is not None:
+            wanted = view.minimumSizeHint().width()
+            check(
+                wanted <= _MIN_PANEL_WIDTHS["mesh3d"],
+                f"the 3D pane needs {wanted} px, the window reserves "
+                f"{_MIN_PANEL_WIDTHS['mesh3d']}",
+            )
+
+        # One state, two controls: toggling either one twenty times must not drift,
+        # rebuild the view, or leave the menu checkbox disagreeing with the pane.
+        first_view = pane.view
+        for _ in range(20):
+            pane_window.act_finger_3d.setChecked(not pane_window.act_finger_3d.isChecked())
+        check(
+            pane_window.act_finger_3d.isChecked() == bool(pane_window._show_finger_3d),
+            "the View menu entry and the window's 3D flag disagree after 20 toggles",
+        )
+        check(
+            pane.enabled() == bool(pane_window._show_finger_3d),
+            "the 3D pane's own state drifted from the window's after 20 toggles",
+        )
+        check(
+            pane.view is first_view,
+            "toggling the 3D pane rebuilt the view (a per-toggle allocation)",
+        )
+
+        pane.close_view()
+        pane.close_view()
+        check(True, "closing the 3D pane twice is safe")
+    finally:
+        pane_window.close()
+        app.processEvents()
+
     section("replay")
     replay_root = APP_ROOT / "outputs" / "_replay_check"
     _shutil.rmtree(replay_root, ignore_errors=True)