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/maps/availability.js

@@ -1,4 +1,8 @@
-import { keySetupRequirement } from '../keySetupCore.mjs';
+import {
+  keySetupRequirement,
+  keySetupRequirementEnvVars,
+} from '../keySetupCore.mjs';
+import { t } from '../i18n/index.js';
 /**
  * Why Google 3D is unavailable, phrased so the tooltip and toast recommend the
  * RIGHT fix. With no credentials the fix is a key (or the ion route); with a
@@ -11,5 +15,6 @@ import { keySetupRequirement } from '../keySetupCore.mjs';
 export function photorealUnavailableReason(hasCredentials) {
   if (hasCredentials)
     return "Google 3D tiles unavailable — check the key's API restrictions, quota, or network";
-  return `${keySetupRequirement('google-maps')} — or a Cesium ion token for the ion-hosted route`;
+  const envVars = keySetupRequirementEnvVars('google-maps');
+  return `${t('setup.keySetup.requirement', { envVars })} — or a Cesium ion token for the ion-hosted route`;
 }

src/maps/defaultSources.js

@@ -1,6 +1,7 @@
 import { MAP_STACKS } from './catalog.js';
 import { photorealUnavailableReason } from './availability.js';
-import { keySetupRequirement } from '../keySetupCore.mjs';
+import { keySetupRequirementEnvVars } from '../keySetupCore.mjs';
+import { t } from '../i18n/index.js';
 import {
   createOsmImagery,
   createEsriImagery,
@@ -34,7 +35,9 @@ export function createDefaultMapSources({
         descriptor,
         available: !descriptor.requiresIon || hasIon,
         unavailableReason: descriptor.requiresIon
-          ? keySetupRequirement('cesium-ion')
+          ? t('setup.keySetup.requirement', {
+              envVars: keySetupRequirementEnvVars('cesium-ion'),
+            })
           : null,
       };
       if (descriptor.kind === 'photoreal')