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/hudLayoutPolicy.js

@@ -1,7 +1,2 @@
 /** Browser-free layout vocabulary shared by UI and server-side voice tools. */
-export const HUD_LAYOUTS = Object.freeze([
-  'tactical',
-  'operator',
-  'minimal',
-  'cyber',
-]);
+export const HUD_LAYOUTS = Object.freeze(['tactical', 'minimal', 'cyber']);