Remove the Operator HUD layout

Display > HUD > Layout and the set_hud voice action now offer Tactical,
Minimal and Cyber. The Operator option, its CSS and its QA coverage are
removed, and the unused "Operator" translations are pruned.

Share-link codes are append-only, so operator keeps its hudVariant code.
A link, scene or saved state that names it restores the default Tactical
layout. The voice schema pins keep their legacy digests by restoring the
retired value before comparing; the full-payload digest is re-derived.

src/i18n/locales/zh-CN.json

@@ -2616,7 +2616,6 @@
   "Layout": "布局",
   "HUD layout": "HUD 布局",
   "Tactical": "战术",
-  "Operator": "操作员",
   "Minimal": "精简",
   "Cyber": "赛博",
   "Sonar": "声呐",