feat(i18n): presentation extraction — t() call sites, data-i18n templates, locale selector

Route every application-owned presentation string through the i18n
core: t() call sites across the app/layers/ui/data/voice surfaces,
data-i18n* attributes in the src/ui/templates/*.html markup (applied at
boot by applyDocumentTranslations from src/standalone/application.js),
and the dock locale selector (runtime-rendered from the offered pair —
a single EN button while only English ships).

Rebased onto current main, where the extraction follows the module
splits: the shell wiring now lands in the owner modules
(panelChrome, visualSettings, locationNavigation, shareRestoration,
shellFeedback, applicationShell) and the voice status corpus in the
realtime* modules; scene status lives in director.js +
playbackAdapter.js.

Modules shared with the node runtime (loadingFeedback,
installationFeedback, regionalModel, keySetupCore, vessels ingestion)
stay environment-neutral English and localize at their browser render
sites (chip maps in shellFeedback/installations controls, the weather
table in cockpitBriefing, keySetupRequirementEnvVars compositions), so
the package-boundary graph stays clean; the browser boundary groups
now own the i18n modules they reach (scripts/package-boundaries.json).

src/layers/cctv/headingConfidence.js

@@ -1,3 +1,5 @@
+import { t } from '../../i18n/index.js';
+
 /**
  * @module headingConfidence
  *
@@ -43,5 +45,9 @@ export function isHeadingEstimated(camera) {
  */
 export function headingHudToken(camera) {
   const hdg = Math.round(Number(camera?.headingDeg) || 0);
-  return `HDG ${hdg}°${isHeadingEstimated(camera) ? ' (ESTIMATED)' : ''}`;
+  // The token copy lives in the layers catalog (en is byte-identical to the
+  // literals these replace); presentation stays here, translation at read.
+  return isHeadingEstimated(camera)
+    ? t('layers.cctv.summary.hdgEstimated', { value: hdg })
+    : t('layers.cctv.summary.hdg', { value: hdg });
 }