Unify auth into refresh-token cookie sessions; server-authoritative nodes and Cyberhack

Auth was effectively broken for every login path: the Telegram handler
built a Set-Cookie header but never attached it to the response, and
Ghost Protocol (seed) login never set a cookie at all — so billing, the
game, and admin actions never actually worked once the frontend was fixed
to stop trying to read an HttpOnly cookie from JS. Replaced the bare
10-minute JWT with AuthService::issue_session: a 15-minute access cookie
plus a rotating 30-day refresh cookie (opaque token, only its SHA-256
hash stored in the new refresh_sessions table); reusing an already-
rotated refresh token now revokes every session for that user. CSRF/CORS
origin allowlists moved from a single hardcoded domain to env-configured
lists so the same session works across the landing and account subdomains.
The bot's WebApp deep links (Личный Кабинет/Тарифы/Синдикат) now bridge
through a short-lived bootstrap token exchanged via POST /auth/exchange
instead of a bare access token in the URL.

Nodes: /nodes/routing now serializes the tunnel_* fields, public_key,
sni_domain and a one-time session token gated on an active subscription
instead of a stub ip/port/protocol list; node provisioning returns 202
immediately and finishes in the background instead of blocking the
request for the whole SSH run; a new background task TCP-pings nodes
every 60s and flips online/offline itself; admin can now force-restart a
node over SSH.

Billing: TON exchange rate is cached in Redis (60s) instead of hitting
TonAPI on every invoice, and the request/response now actually uses the
requested currency and TonAPI's real (uppercase) key casing — previously
only USD/RUB were ever requested and the lookup used the wrong case, so
non-USD/RUB plans could never price correctly.

Cyberhack: the server now generates and stores the board itself and
replays the client's raw click path to compute the score, instead of
clamping a client-reported number — closes the "final score is whatever
the browser sends" hole flagged in the security audit.

Frontend: api.ts no longer tries to read the HttpOnly session cookie from
JS (that never worked) and instead relies on same-origin credentials plus
a silent refresh-and-retry on 401; AdminDashboard's restart/delete actions
are wired up; Auth.tsx drops the artificial delays and requires an
explicit seed download/confirmation before continuing, since a lost Ghost
seed is unrecoverable.

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

src/db/README.md

@@ -1,8 +1,8 @@
 # `db/` — доступ к данным
 
 - **`models.rs`** — табличные структуры (`#[derive(FromRow)]`: `User`, `Subscription`,
-  `VpnNode`, `PromoCode`) и производные DTO, которые уходят напрямую в JSON API
-  (`ProfileData`, `SubscriptionData`, `ReferralData`).
+  `VpnNode`, `PromoCode`, `RefreshSession`) и производные DTO, которые уходят напрямую в
+  JSON API (`ProfileData`, `SubscriptionData`, `ReferralData`).
 - **`repository.rs`** — трейт [`AppRepository`] (единая граница между `modules::*::service`
   и Postgres) и его единственная реализация `PgRepository`. Сервисы модулей зависят
   только от трейта (`Arc<dyn AppRepository>`), не от конкретной СУБД.
@@ -22,10 +22,12 @@
 
 | Операция | Защита |
 |---|---|
-| `consume_ticket_and_reward` (билет Cyberhack) | `SELECT ... FOR UPDATE` по юзеру |
+| `start_hack_session` (билет Cyberhack) | `SELECT ... FOR UPDATE` по юзеру |
+| `consume_hack_session` (сдача результата) | `UPDATE ... WHERE used_at IS NULL RETURNING` — повторная сдача одной сессии невозможна |
 | `apply_promo_code` | `SELECT ... FOR UPDATE` по промокоду + `UNIQUE(promo_id, user_id)` |
 | `reward_referrer` | `UPDATE ... RETURNING` атомарно проверяет и переводит статус реферала |
 | Инвойсы | `invoices.external_id` — `UNIQUE`, поэтому один tx-хеш нельзя засчитать дважды |
+| `refresh_session` (ротация refresh-токена) | `UPDATE ... WHERE revoked_at IS NULL` — повторное использование отозванного токена отзывает все сессии юзера |
 
 ## Модели, для которых важно помнить о NULL