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/ui/cockpitTrackingController.js

@@ -1,4 +1,5 @@
 /** Tracking identity, entry, exit and contact navigation for the Cockpit controller. */
+import { t } from '../i18n/index.js';
 import {
   normalizeHeading,
   resolveTrackedAircraftInfo,
@@ -58,8 +59,8 @@ export function syncTr3bToggle(info) {
   this.tr3bToggle.hidden = !icao24;
   this.tr3bToggle.setAttribute('aria-pressed', converted ? 'true' : 'false');
   this.tr3bToggle.title = converted
-    ? 'Restore real aircraft'
-    : 'Reclassify as TR-3B';
+    ? t('cockpit.context.tr3bRestoreTitle')
+    : t('cockpit.context.tr3bTitle');
 }
 
 export function syncEntry() {
@@ -183,15 +184,21 @@ export function enter() {
   this.showBriefPage(0);
   this.startBriefRotation();
   const trackLabel =
-    info.callsign || info.registration || info.icao24 || 'AIRCRAFT';
+    info.callsign ||
+    info.registration ||
+    info.icao24 ||
+    t('cockpit.hud.fallbackCallsign');
   const trackHeading = String(
     Math.round(normalizeHeading(info.track ?? 0)),
   ).padStart(3, '0');
   this.pushCockpitSignal(
     'track',
     'track',
-    'TRACK ACQUIRED',
-    `${trackLabel} · COURSE ${trackHeading}°`,
+    t('cockpit.signal.trackAcquired'),
+    t('cockpit.signal.trackDetail', {
+      label: trackLabel,
+      heading: `${trackHeading}°`,
+    }),
   );
   this.updateHud(info, performance.now(), true);
   this.setVisionMode(this.visionMode);