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/flights/tracking.js

@@ -1,4 +1,5 @@
 import * as Cesium from 'cesium';
+import { t } from '../../i18n/index.js';
 import { nextCockpitNearContacts } from '../../data/cockpitAirLod.js';
 import { trackedModelZoomActive } from '../../data/trackedModelRegime.js';
 import {
@@ -755,7 +756,7 @@ export function createTracking({
     const spd = info.velocity ? `${Math.round(info.velocity * 1.944)} kts` : '';
     const stale =
       flightState.records.missingPolls.get(icao24) || flightState.feed._backoff
-        ? 'STALE'
+        ? t('layers.status.stale')
         : '';
     const lines = [[cs, fl, spd, stale].filter(Boolean).join(' · ')];
     // Converted contacts report their class as TR-3B and nothing else — the