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/panelPositionControls.js

@@ -1,4 +1,5 @@
 /** Own panel position preferences, viewport clamping and drag listeners. */
+import { t } from '../i18n/index.js';
 /** Versioned localStorage namespace prefix to invalidate stale panel layouts. */
 const PANEL_LAYOUT_STORAGE_VERSION = 'v6';
 /**
@@ -55,9 +56,7 @@ export class PanelPositionControls {
         key.startsWith('godsEyeView.v6.panelPos.'),
       );
       if (hadOldPositions) {
-        this._showToast(
-          'Panel layout updated — positions reset to new defaults',
-        );
+        this._showToast(t('cockpit.panel.layoutResetToast'));
       }
     } catch {
       // storage unavailable