Add animated startup splash + live server transfer dialog

Splash: pulsing logo, client->server packet-flow animation, cycling
status steps and a shimmer bar, shown for ~1s while the session restores.

Transfer progress: the backend now streams p4 sync/submit stdout line by
line (throttled ~25fps) and emits p4-transfer events; the frontend shows a
P4V-style progress dialog (op title, current file, file count, animated
bar) that only appears once an operation runs past ~400ms. Replaces the old
submit-only modal. All new strings translated (5 langs).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/i18n.ts

@@ -27,6 +27,17 @@ const D: Record<string, Tr> = {
   "Close": { ru: "Закрыть", de: "Schließen", fr: "Fermer", es: "Cerrar" },
   "Theme": { ru: "Тема", de: "Thema", fr: "Thème", es: "Tema" },
   "Restoring session…": { ru: "Восстановление сессии…", de: "Sitzung wird wiederhergestellt…", fr: "Restauration de la session…", es: "Restaurando sesión…" },
+  // startup splash
+  "Connecting to server…": { ru: "Подключение к серверу…", de: "Verbinde mit Server…", fr: "Connexion au serveur…", es: "Conectando al servidor…" },
+  "Authenticating…": { ru: "Авторизация…", de: "Authentifizierung…", fr: "Authentification…", es: "Autenticando…" },
+  "Loading workspace…": { ru: "Загрузка workspace…", de: "Workspace wird geladen…", fr: "Chargement du workspace…", es: "Cargando workspace…" },
+  "Syncing state…": { ru: "Синхронизация…", de: "Zustand wird synchronisiert…", fr: "Synchronisation…", es: "Sincronizando…" },
+  // server transfer dialog
+  "Submitting to server": { ru: "Отправка на сервер", de: "Wird an Server gesendet", fr: "Envoi au serveur", es: "Enviando al servidor" },
+  "Getting latest from server": { ru: "Загрузка с сервера", de: "Neueste Version wird geladen", fr: "Récupération depuis le serveur", es: "Obteniendo del servidor" },
+  "{n} files": { ru: "{n} файлов", de: "{n} Dateien", fr: "{n} fichiers", es: "{n} archivos" },
+  "Uploading…": { ru: "Отправка…", de: "Wird hochgeladen…", fr: "Envoi…", es: "Subiendo…" },
+  "Downloading…": { ru: "Скачивание…", de: "Wird heruntergeladen…", fr: "Téléchargement…", es: "Descargando…" },
 
   // connect screen
   "Connect to Perforce": { ru: "Подключение к Perforce", de: "Mit Perforce verbinden", fr: "Se connecter à Perforce", es: "Conectar a Perforce" },