Render: integrated workspace, preview image jobs and opaque PBR (#1046)

Lands the Render workspace (R3), bounded preview-image jobs with cancellation and atomic PNG export (R4a), and opaque PBR looks as one change.

- Render workspace: an overlay-free product preview on the installed GPU device. Returning to Design restores its camera. render.scene and render.settings.apply are added.
- Image jobs: render.preflight/start/status/cancel/export run bounded CPU preview jobs. Export captures the job, overwrite choice and document, and checks the caller's file scope before writing.
- Opaque PBR: looks can carry metal fraction, roughness and dielectric IOR. The product viewport and preview PNG use them; geometry and mass are unchanged. The v1 catalog export refuses PBR rather than dropping it.
- Render setups and PBR looks are saved under design format 21. Labels are in en/de/ja/ko/zh/ru.

Supersedes #706 and #800. Refs #620, #673, #756, #1004.

Contributed by @0xlillith.

Co-authored-by: lillith <35337584+0xlillith@users.noreply.github.com>

assets/locales/zh.json

@@ -1046,5 +1046,59 @@
   "update.dmg_opened": "磁盘映像已校验并打开:将 SolidCraft 拖到“应用程序”替换旧版本,然后重启 SolidCraft。",
   "update.install_failed": "更新未安装:{error}。未做任何更改;可用“下载”获取安装包。",
   "cmd.render_settings_get": "渲染设置",
-  "cmd.render_settings_set": "保存渲染设置"
+  "cmd.render_settings_set": "保存渲染设置",
+  "cmd.render_scene": "检查渲染场景",
+  "cmd.render_settings_apply": "应用渲染相机",
+  "toolbar.render": "渲染",
+  "toolbar.render_scene": "场景",
+  "render.preview": "集成预览",
+  "render.preview_help": "光栅着色和混合透明度。暂不支持折射、HDRI 和最终渲染。",
+  "render.setup_name": "设置名称",
+  "render.background": "场景背景",
+  "render.perspective": "透视相机",
+  "render.fit": "适配产品视图",
+  "render.restore_camera": "恢复已保存相机",
+  "render.save_setup": "保存设置",
+  "render.unsaved": "未保存的预览更改",
+  "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.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",
+  "render.image_width": "宽度",
+  "render.image_height": "高度",
+  "render.image_transparent": "透明背景",
+  "render.image_check": "检查渲染请求",
+  "render.image_supported": "支持此渲染请求；开始时将再次检查队列和内存池。",
+  "render.image_queued": "等待渲染",
+  "render.image_preparing": "正在准备图像",
+  "render.image_running": "正在渲染图像",
+  "render.image_encoding": "正在编码 PNG",
+  "render.image_cancelling": "正在取消",
+  "render.image_cancelled": "渲染已取消",
+  "render.image_completed": "图像可导出",
+  "render.image_failed": "渲染失败",
+  "render.image_unknown": "渲染状态不可用",
+  "render.image_reduce": "请尝试更小的图像或更简单的场景。",
+  "render.image_cancel": "取消渲染",
+  "render.image_stale": "此图像使用后续更改之前捕获的场景。",
+  "render.image_start": "开始渲染",
+  "render.image_overwrite": "替换现有文件",
+  "render.image_export": "导出 PNG",
+  "cmd.render_preflight": "检查渲染请求",
+  "cmd.render_start": "渲染图像",
+  "cmd.render_status": "渲染进度",
+  "cmd.render_cancel": "取消渲染",
+  "cmd.render_export": "导出 PNG",
+  "toolbar.image": "图像",
+  "appearance.surface_response": "表面响应",
+  "appearance.pbr_opaque": "不透明 PBR",
+  "appearance.metallic": "金属度",
+  "appearance.roughness": "粗糙度",
+  "appearance.dielectric_ior": "电介质折射率",
+  "appearance.pbr_help": "在渲染工作区或产品 PNG 中查看此表面。不支持折射或透射。",
+  "render.opaque_preview_help": "不透明 PBR 和纯色；透明效果使用混合。不支持折射、HDRI 和最终渲染。",
+  "render.opaque_image_summary": "预览 PNG · 不透明 PBR · 混合透明"
 }