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/app/scene.js

@@ -14,6 +14,7 @@ import {
   governorRequestRender,
 } from '../renderGovernor.js';
 import { describeError } from './errors.js';
+import { t } from '../i18n/index.js';
 
 /** Construct the application globe using the caller's local configuration. */
 export async function createApplicationScene({
@@ -41,7 +42,7 @@ export async function createApplicationScene({
       else window.__GOOGLE_MAPS_API_KEY__ = previousKey;
     });
   }
-  loaderStatus.textContent = 'Configuring viewer...';
+  loaderStatus.textContent = t('shell.loading.status.configuring');
   // Provider attribution stays visible, including clean-view and recording.
   const creditContainer = document.createElement('div');
   creditContainer.id = 'cesium-credits';
@@ -60,8 +61,8 @@ export async function createApplicationScene({
   configureCreditKeyboardAccess(document);
   loaderStatus.textContent =
     googleApiKey || cesiumToken
-      ? 'Loading Google 3D Tiles...'
-      : 'Loading the keyless globe...';
+      ? t('shell.loading.status.tilesGoogle')
+      : t('shell.loading.status.tilesKeyless');
   const photoreal = await loadPhotorealisticTileset(Cesium, {
     googleApiKey,
     cesiumToken,
@@ -88,12 +89,14 @@ export async function createApplicationScene({
         tileError,
       );
       const tileErrorDetail = describeError(tileError);
-      loaderStatus.textContent = `Google 3D Tiles unavailable (${tileErrorDetail}). Loading the keyless globe...`;
+      loaderStatus.textContent = t('shell.loading.status.tilesUnavailable', {
+        detail: tileErrorDetail,
+      });
     }
     viewer.scene.globe.show = true;
   }
 
-  loaderStatus.textContent = 'Initializing systems...';
+  loaderStatus.textContent = t('shell.loading.status.systems');
 
   const mapStackController = new MapController(viewer, {
     requestRender: governorRequestRender,