Add seed/Telegram login button and traffic usage indicator

New non-blocking login panel on the Home screen (seed backup/restore +
Telegram magic-link via the bot deep-link, polled through the new backend
endpoints) — uses its own popover instead of a full-screen Dialog so the
burger menu stays clickable while it's open. VpnStats now shows a used/limit
usage bar backed by a new useUsageStore.

Also registers tauri-plugin-shell (needed to open the t.me deep-link) and
threads an optional auth token from the app down through TunnelConfig to the
proxy client (desktop + Android), for instances running --require-auth.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/locales/en.json

@@ -40,5 +40,25 @@
   "tg_title": "Secure Session",
   "tg_desc": "Lost access to Telegram and can't renew your subscription? Start a secure session. This built-in client routes your traffic strictly through our VPN tunnel.",
   "tg_start_btn": "Start Session",
-  "tg_connecting": "Establishing secure connection..."
+  "tg_connecting": "Establishing secure connection...",
+  "usage_label": "Data used",
+  "usage_unlimited": "Unlimited",
+  "login_button": "Log in",
+  "login_title": "Account access",
+  "login_tab_seed": "Seed",
+  "login_tab_telegram": "Telegram",
+  "login_seed_current_label": "Your current seed",
+  "login_seed_copy": "Copy",
+  "login_seed_copied": "Copied",
+  "login_seed_no_seed": "This account is linked to Telegram and has no seed of its own.",
+  "login_seed_input_label": "Log in with an existing seed",
+  "login_seed_input_placeholder": "Paste your seed phrase",
+  "login_seed_submit": "Log in",
+  "login_seed_invalid": "Invalid or unknown seed",
+  "login_telegram_desc": "Log in via the Netrunner Telegram bot to link this account across devices.",
+  "login_telegram_start": "Log in via Telegram",
+  "login_telegram_waiting": "Waiting for confirmation in Telegram...",
+  "login_telegram_success": "Login confirmed!",
+  "login_telegram_error": "Login failed or expired, try again",
+  "login_telegram_cancel": "Cancel"
 }

src/locales/ru.json

@@ -40,5 +40,25 @@
   "tg_title": "Защищенная сессия",
   "tg_desc": "Нет доступа к Telegram, чтобы оплатить или продлить подписку? Запустите безопасную сессию. Этот встроенный клиент гарантированно направит трафик через наш VPN-туннель.",
   "tg_start_btn": "Начать сессию",
-  "tg_connecting": "Установка защищенного соединения..."
+  "tg_connecting": "Установка защищенного соединения...",
+  "usage_label": "Расход трафика",
+  "usage_unlimited": "Безлимит",
+  "login_button": "Войти",
+  "login_title": "Доступ к аккаунту",
+  "login_tab_seed": "Seed",
+  "login_tab_telegram": "Telegram",
+  "login_seed_current_label": "Ваш текущий seed",
+  "login_seed_copy": "Копировать",
+  "login_seed_copied": "Скопировано",
+  "login_seed_no_seed": "Этот аккаунт привязан к Telegram и не имеет собственного seed.",
+  "login_seed_input_label": "Войти по существующему seed",
+  "login_seed_input_placeholder": "Вставьте seed-фразу",
+  "login_seed_submit": "Войти",
+  "login_seed_invalid": "Неверный или неизвестный seed",
+  "login_telegram_desc": "Войдите через Telegram-бота Netrunner, чтобы привязать аккаунт на всех устройствах.",
+  "login_telegram_start": "Войти через Telegram",
+  "login_telegram_waiting": "Ожидание подтверждения в Telegram...",
+  "login_telegram_success": "Вход подтверждён!",
+  "login_telegram_error": "Не удалось войти или срок истёк, попробуйте снова",
+  "login_telegram_cancel": "Отмена"
 }