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/mapSourceControls.js

@@ -1,4 +1,5 @@
 import { renderMapStackChips, syncMapStackChips } from '../mapStackChips.js';
+import { t } from '../i18n/index.js';
 
 /**
  * Own Map Source presentation and selection without constructing map providers.
@@ -28,7 +29,9 @@ export function createMapSourceControls({
       statusElement.textContent =
         state.status === 'switching'
           ? '...'
-          : stack?.shortLabel || stack?.label || 'MAP';
+          : stack?.shortLabel ||
+            stack?.label ||
+            t('cockpit.presets.mapStackFallback');
       statusElement.classList.toggle('warn', !!state.lastError);
     }
   }