Render preview uses the shared camera navigation (#1462)

* Render preview uses the shared camera navigation

The Render workspace's product preview had its own hard-coded camera
controls. Camera input now lives in one component, navigation::handle,
which the modelling viewport and the Render preview both call (NavCaps:
orbit, pick). Render gets the navigation preset, Orbit around, zoom to the
cursor, the middle double-click and the axis view or navigation cube.
Flat pages can call it with orbit off. A test rejects pages that read the
wheel or move the camera themselves.

Fixes #1454

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Render panel hint says the camera moves as in Design

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

assets/locales/zh.json

@@ -1125,7 +1125,7 @@
   "render.reload_settings": "重新加载已保存设置",
   "render.unavailable_preview": "此设置请求了不可用的预览配置。",
   "render.use_preview": "使用集成预览",
-  "render.navigation_help": "拖动以旋转，按住中键拖动以平移，滚动以缩放。保存设置会记录当前相机。",
+  "render.navigation_help": "相机的操作与设计中相同（首选项 › 导航）。保存设置会记录当前相机。",
   "render.return_design": "返回设计",
   "render.image_title": "渲染图像",
   "render.image_help": "CPU 预览图像 · PNG · 近似透明度",