feat(#239): add angular i18n shell namespace bridge

frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts

@@ -26,13 +26,13 @@ describe('i18n MVP flow smoke (host/player + audio policy)', () => {
     host.ngOnInit();
     player.ngOnInit();
 
-    expect(host.copy('host.start_round')).toBe('Start round');
+    expect(host.copy('game.host.start_round')).toBe('Start round');
-    expect(player.copy('player.submit_guess')).toBe('Submit guess');
+    expect(player.copy('game.player.submit_guess')).toBe('Submit guess');
 
     setPreferredLocale('da');
 
-    expect(host.copy('host.start_round')).toBe('Start runde');
+    expect(host.copy('game.host.start_round')).toBe('Start runde');
-    expect(player.copy('player.submit_guess')).toBe('Send gæt');
+    expect(player.copy('game.player.submit_guess')).toBe('Send gæt');
 
     player.ngOnDestroy();
     host.ngOnDestroy();

frontend/angular/src/app/lobby-i18n.spec.ts

@@ -93,6 +93,36 @@ describe('lobby i18n locale propagation', () => {
     }
   });
 
+  it('resolves baseline shell/game keys from shared namespaces', async () => {
+    vi.stubGlobal('window', {
+      location: { search: '' },
+      localStorage: storageMock({ 'wpp.locale': 'da' }),
+    });
+    vi.stubGlobal('navigator', { language: 'da-DK' });
+
+    const i18n = await import('./lobby-i18n');
+
+    const baselineKeys = [
+      'lobby.shell.title',
+      'lobby.shell.host_nav',
+      'lobby.shell.player_nav',
+      'lobby.shell.language_label',
+      'common.refresh',
+      'common.session_code',
+      'game.host.title',
+      'game.host.start_round',
+      'game.player.title',
+      'game.player.submit_guess',
+    ] as const;
+
+    for (const key of baselineKeys) {
+      const value = i18n.t(key, 'da');
+      expect(value).toBeTypeOf('string');
+      expect(value.length).toBeGreaterThan(0);
+      expect(value).not.toBe(key);
+    }
+  });
+
   it('exposes primary-only audio routing policy to clients', async () => {
     vi.stubGlobal('window', {
       location: { search: '' },

frontend/angular/src/app/lobby-i18n.ts

@@ -65,10 +65,23 @@ export function subscribeToLocaleChanges(callback: (locale: SupportedLocale) =>
   };
 }
 
+function resolveCatalogPath(key: string): string {
+  if (key.startsWith('lobby.shell.')) {
+    return key.replace(/^lobby\.shell\./, 'app.');
+  }
+  if (key.startsWith('game.host.')) {
+    return key.replace(/^game\.host\./, 'host.');
+  }
+  if (key.startsWith('game.player.')) {
+    return key.replace(/^game\.player\./, 'player.');
+  }
+  return key;
+}
+
 export function t(key: string, locale: string): string {
   const normalizedLocale = normalizeLocale(locale);
   const fallbackLocale = DEFAULT_LOCALE;
-  const segments = key.split('.');
+  const segments = resolveCatalogPath(key).split('.');
 
   let cursor: unknown = lobbyCatalog.frontend.ui;
   for (const segment of segments) {