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/submarineCables/ingestion.js

@@ -1,3 +1,4 @@
+import { t } from '../../i18n/index.js';
 import {
   featureLabel,
   featureReference,
@@ -11,7 +12,7 @@ export function createIngestion({ state, parts, source }) {
 
     state._loading = true;
     state._error = null;
-    state._loadingLabel = 'loading...';
+    state._loadingLabel = t('layers.meta.loading');
     // Ownership token (the militaryAwareness activationId pattern): a
     // disable/abort followed by a fresh enable starts a NEWER load while this
     // one is still settling. The stale load must bail after every await and