feat: add language selector to login screen, default to English

Without a stored preference, the app always started in German even for
non-German speakers who had never seen a settings screen. English as the
fallback and a visible selector on the login screen mean the UI is
navigable before any account connection.

src/renderer/src/context/SettingsContext.tsx

@@ -25,7 +25,7 @@ const DEFAULTS: AppSettings = {
   badgeGap: BADGE_GAP_DEFAULT,
   hlsCacheEnabled: false,
   fileLoggingEnabled: false,
-  language: 'de'
+  language: 'en'
 }
 
 export { SIDEBAR_MIN, SIDEBAR_MAX, SIDEBAR_DEFAULT, BADGE_GAP_MIN, BADGE_GAP_MAX, BADGE_GAP_DEFAULT }

src/renderer/src/i18n/de.ts

@@ -48,6 +48,7 @@ export const de = {
   'login.expiresIn': 'Code läuft in {time} ab.',
   'login.error.accessDenied': 'Zugriff abgelehnt.',
   'login.error.expired': 'Code abgelaufen — bitte erneut versuchen.',
+  'login.languageSelect': 'Sprachauswahl',
 
   // ─── Following ──────────────────────────────────────────────────────────
   'following.loading': 'Lade Kanäle…',

src/renderer/src/i18n/en.ts

@@ -49,6 +49,7 @@ export const en: Messages = {
   'login.expiresIn': 'Code expires in {time}.',
   'login.error.accessDenied': 'Access denied.',
   'login.error.expired': 'Code expired — please try again.',
+  'login.languageSelect': 'Language',
 
   // ─── Following ──────────────────────────────────────────────────────────
   'following.loading': 'Loading channels…',

src/renderer/src/i18n/useT.ts

@@ -20,7 +20,7 @@ function interpolate(raw: string, vars?: Record<string, string | number>): strin
 
 export function useT(): TranslateFn {
   const { settings } = useSettings()
-  const table = TABLES[settings.language] ?? de
+  const table = TABLES[settings.language] ?? en
   return useCallback((key: MessageKey, vars?: Record<string, string | number>): string =>
     interpolate(table[key], vars), [table])
 }
@@ -36,7 +36,7 @@ export function getActiveLanguage(): Language {
       if (parsed.language === 'en' || parsed.language === 'de') return parsed.language
     }
   } catch { /* ignore */ }
-  return 'de'
+  return 'en'
 }
 
 export function tStatic(key: MessageKey, vars?: Record<string, string | number>): string {

src/renderer/src/screens/LoginScreen.tsx

@@ -2,6 +2,7 @@ import { useEffect, useRef, useState } from 'react'
 import QRCode from 'qrcode'
 import type { DeviceFlowStartInfo } from '../types/t4sd'
 import { useT } from '../i18n/useT'
+import { useSettings } from '../context/SettingsContext'
 
 interface Props {
   onAuthorized: () => void
@@ -16,8 +17,11 @@ type Phase =
 
 export default function LoginScreen({ onAuthorized }: Props): JSX.Element {
   const t = useT()
+  const { settings, setLanguage } = useSettings()
   const [phase, setPhase] = useState<Phase>({ kind: 'idle' })
   const startBtnRef = useRef<HTMLButtonElement>(null)
+  const langEnRef = useRef<HTMLButtonElement>(null)
+  const langDeRef = useRef<HTMLButtonElement>(null)
 
   // On mount: check whether the client ID is configured.
   useEffect(() => {
@@ -29,9 +33,21 @@ export default function LoginScreen({ onAuthorized }: Props): JSX.Element {
 
   useEffect(() => {
     const onKey = (e: KeyboardEvent): void => {
-      if (e.key !== 'Enter') return
-      if (phase.kind === 'idle' || phase.kind === 'error') void start()
-      else if (phase.kind === 'awaiting') void cancel()
+      const active = document.activeElement
+      if (e.key === 'ArrowRight' && active === langEnRef.current) {
+        langDeRef.current?.focus()
+      } else if (e.key === 'ArrowLeft' && active === langDeRef.current) {
+        langEnRef.current?.focus()
+      } else if (e.key === 'ArrowDown' && active === startBtnRef.current) {
+        langEnRef.current?.focus()
+      } else if (e.key === 'ArrowUp' && (active === langEnRef.current || active === langDeRef.current)) {
+        startBtnRef.current?.focus()
+      } else if (e.key === 'Enter') {
+        if (active === langEnRef.current) { setLanguage('en'); return }
+        if (active === langDeRef.current) { setLanguage('de'); return }
+        if (phase.kind === 'idle' || phase.kind === 'error') void start()
+        else if (phase.kind === 'awaiting') void cancel()
+      }
     }
     window.addEventListener('keydown', onKey)
     return () => window.removeEventListener('keydown', onKey)
@@ -134,6 +150,27 @@ export default function LoginScreen({ onAuthorized }: Props): JSX.Element {
       >
         {phase.kind === 'starting' ? t('login.starting') : t('login.connect')}
       </button>
+      <div className="login__lang-select">
+        <span className="login__lang-label">{t('login.languageSelect')}</span>
+        <div className="login__lang-buttons">
+          <button
+            ref={langEnRef}
+            className={`login__lang-btn${settings.language === 'en' ? ' login__lang-btn--active' : ''}`}
+            onClick={() => setLanguage('en')}
+            aria-label="English"
+          >
+            🇺🇸
+          </button>
+          <button
+            ref={langDeRef}
+            className={`login__lang-btn${settings.language === 'de' ? ' login__lang-btn--active' : ''}`}
+            onClick={() => setLanguage('de')}
+            aria-label="Deutsch"
+          >
+            🇩🇪
+          </button>
+        </div>
+      </div>
     </div>
   )
 }

src/renderer/src/styles/global.css

@@ -149,6 +149,58 @@ body,
   color: #ff6868;
 }
 
+.login__lang-select {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 10px;
+  margin-top: 4px;
+}
+
+.login__lang-label {
+  font-size: 13px;
+  color: var(--color-fg-dim);
+  letter-spacing: 0.04em;
+  text-transform: uppercase;
+}
+
+.login__lang-buttons {
+  display: flex;
+  gap: 12px;
+}
+
+.login__lang-btn {
+  width: 80px;
+  height: 56px;
+  font-size: 36px;
+  line-height: 1;
+  border-radius: 10px;
+  border: 2px solid rgba(255, 255, 255, 0.12);
+  background: rgba(255, 255, 255, 0.04);
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  transition: border-color 0.15s, background 0.15s;
+  outline: none;
+}
+
+.login__lang-btn:hover,
+.login__lang-btn:focus {
+  border-color: rgba(255, 255, 255, 0.4);
+  background: rgba(255, 255, 255, 0.08);
+}
+
+.login__lang-btn--active {
+  border-color: var(--color-accent);
+  background: rgba(145, 71, 255, 0.15);
+}
+
+.login__lang-btn--active:focus {
+  border-color: var(--color-accent);
+  background: rgba(145, 71, 255, 0.25);
+}
+
 /* ── App Layout (post-auth) ───────────────────────── */
 .app-layout {
   display: grid;