Add i18n foundation and translations (#1027)

* feat: add i18n foundation

* feat: localize sessions sidebar

* Localize multirun/scheduled tasks and fix dialog dropdown interactions

* localize git sidebar surface and add zh-CN keys

* feat(ui): localize context panel, diff/plan views, and context sidebar content

* fix(config): resolve user config home via fs/home before embedded home

* localize header/chat UI and complete model/worktree panel strings

* localize worktree + github issue/pr dialog flows

* localize settings sections and split settings i18n dictionaries

* localize additional settings sections and sidebars

* localize more settings pages and dialogs

* fix settings select trigger localization

* localize tunnel settings ui surface

* localize additional settings sections

* localize keyboard shortcuts labels in settings

* localize terminal and utility dialogs surfaces

* feat(i18n): localize remaining UI strings

* Add Ukrainian locale

* Add Spanish locale

* Add Brazilian Portuguese locale

* Polish locale translations

packages/ui/src/components/layout/MainLayout.tsx

@@ -20,6 +20,7 @@ import { useUIStore } from '@/stores/useUIStore';
 import { useUpdateStore } from '@/stores/useUpdateStore';
 import { useDeviceInfo } from '@/lib/device';
 import { useEffectiveDirectory } from '@/hooks/useEffectiveDirectory';
+import { useI18n } from '@/lib/i18n';
 import { cn } from '@/lib/utils';
 import { isDesktopShell } from '@/lib/desktop';
 import { lazyWithChunkRecovery } from '@/lib/chunkLoadRecovery';
@@ -63,6 +64,7 @@ const normalizeDirectoryKey = (value: string): string => {
 };
 
 export const MainLayout: React.FC = () => {
+    const { t } = useI18n();
     const RIGHT_SIDEBAR_AUTO_CLOSE_WIDTH = 1140;
     const RIGHT_SIDEBAR_AUTO_OPEN_WIDTH = 1220;
     const BOTTOM_TERMINAL_AUTO_CLOSE_HEIGHT = 640;
@@ -696,7 +698,7 @@ export const MainLayout: React.FC = () => {
                             setMobileLeftDrawerOpen(false);
                             setRightSidebarOpen(false);
                         }}
-                        aria-label="Close drawer"
+                        aria-label={t('mainLayout.mobile.closeDrawerAria')}
                     />
                     
                     {/* Left drawer (Session) */}