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/keySetup.test.mjs

@@ -48,7 +48,7 @@ test('setup placement moves the same button only in Cyber and disconnects on tea
     chip,
   );
   assert.equal(chip.parentNode, home);
-  for (const variant of ['cyber', 'operator', 'cyber', 'minimal']) {
+  for (const variant of ['cyber', 'tactical', 'cyber', 'minimal']) {
     theme.dataset.uiTheme = variant;
     notify();
     assert.equal(chip.parentNode, variant === 'cyber' ? toolbar : home);