fix(auth): clarify admin login flow

Use admin-specific Telegram copy and define the missing credential API. Replace predictable bootstrap passwords with random one-time secrets.

docs/backend/ADMIN-CREDENTIAL-AUTH-HANDOFF.md

@@ -0,0 +1,102 @@
+# Admin credential authentication handoff
+
+## Current production state
+
+`admin.gorbushka.market` can authenticate through the existing Telegram
+session flow. Login/password authentication is not implemented by the live
+backend, so the frontend must not validate or embed administrator credentials.
+
+The existing `/admin-login` Ed25519 page is also not production-ready because
+the backend challenge/verify endpoints do not exist.
+
+## Required backend API
+
+Tenant identity comes only from nginx's trusted `X-Storefront-Host` header.
+Never accept a tenant or marketplace identifier from the login request body.
+
+### Create session
+
+```http
+POST /api/identity/v1/session
+Content-Type: application/json
+
+{
+  "login": "gorbushka",
+  "password": "<secret>"
+}
+```
+
+Success:
+
+```json
+{
+  "accessToken": "<short-lived JWT>",
+  "refreshToken": "<rotating opaque token>",
+  "expiresAt": "2026-08-21T04:00:00Z",
+  "mustChangePassword": true,
+  "user": {
+    "id": "<id>",
+    "login": "gorbushka",
+    "displayName": "Gorbushka administrator",
+    "roles": ["MARKETPLACE_ADMIN"],
+    "tenantId": "<tenant-id>"
+  }
+}
+```
+
+Errors:
+
+- `400` malformed request.
+- `401 INVALID_CREDENTIALS` with one generic message for unknown login and
+  wrong password.
+- `403 TENANT_DISABLED` or `TENANT_MISMATCH`.
+- `429 RATE_LIMITED` with `Retry-After`.
+
+### Session lifecycle
+
+```http
+POST   /api/identity/v1/session/refresh
+DELETE /api/identity/v1/session
+POST   /api/identity/v1/session/change-password
+GET    /api/identity/v1/session/permissions
+```
+
+`change-password` accepts `{ currentPassword, newPassword }`. While
+`mustChangePassword` is true, every non-auth admin endpoint returns
+`403 PASSWORD_CHANGE_REQUIRED`.
+
+## Provisioning and security requirements
+
+- Generate a random one-time bootstrap password. Do not use the documented
+  deterministic `{slug}2026$` pattern in production.
+- Store only an Argon2id password hash with a unique salt.
+- Never log passwords, refresh tokens, authorization headers, or session IDs.
+- Rate-limit by tenant, login, and source IP; add exponential backoff.
+- Rotate refresh tokens and revoke the full token family on reuse.
+- Enforce tenant and role authorization on every admin endpoint. Angular
+  guards are UI only.
+- Audit login success/failure, password change, refresh-token reuse, logout,
+  and lockout without recording secrets.
+
+## Required nginx invariants
+
+Backend nginx changes must preserve:
+
+```nginx
+proxy_set_header X-Storefront-Host $storefront_host;
+proxy_set_header Origin "";
+
+add_header Access-Control-Allow-Headers \
+  "Authorization, Content-Type, AdminWebSessionID, WebSessionID, Currency, X-Language, X-Region, X-Requested-With" always;
+```
+
+For `Origin: https://admin.gorbushka.market`, `$storefront_host` must be
+`gorbushka.market`. The API upstream remains `https://127.0.0.1:445` unless
+the backend team deliberately changes the listening address.
+
+## Frontend follow-up after backend delivery
+
+Add the credential form to the admin-only login shell, submit only over HTTPS,
+store the returned admin session separately from customer auth, force the
+password-change screen when requested, and keep Telegram as an optional
+fallback. Do not expose a non-functional credential form before the API ships.

docs/backend/BACKEND-HANDOFF.md

@@ -79,7 +79,7 @@ Nothing here is done yet — this is the setup a backend dev does on day one.
 4. Implement the **bootstrap config endpoint** (§1a) — without it the frontend cannot render for any tenant.
 5. Implement the Telegram session endpoints — the login flow is fully built client-side and blocked only on these.
 6. Implement `GET /api/identity/v1/session/permissions` ([TRACK-S §2](TRACK-S-SECURITY-RBAC-CONTRACT.md)) — frontend route guards derive from it.
-7. Seed per-marketplace bootstrap admins ([TRACK-S §8](TRACK-S-SECURITY-RBAC-CONTRACT.md)): login = marketplace slug, password = `{slug}2026$`, `mustChangePassword: true`.
+7. Seed per-marketplace bootstrap admins ([TRACK-S §8](TRACK-S-SECURITY-RBAC-CONTRACT.md)): login = marketplace slug, cryptographically random one-time password delivered out of band, `mustChangePassword: true`.
 
 Steps 4–6 unblock the entire frontend. Everything after is feature work.
 

docs/backend/TRACK-S-SECURITY-RBAC-CONTRACT.md

@@ -96,7 +96,8 @@ Customer/seller PII is exposed only to roles that need it for their scope (e.g.
 Each marketplace ships with one bootstrap `MARKETPLACE_ADMIN` account, seeded at provisioning time (Phase 9 launch step):
 
 - `login` = marketplace slug (`projectName`)
-- `password` = `{projectName}2026$`, flagged `mustChangePassword: true`
+- `password` = cryptographically random one-time secret delivered out of band,
+  flagged `mustChangePassword: true` (never derive it from the marketplace slug)
 - Login succeeds but every non-auth request 403s with `PASSWORD_CHANGE_REQUIRED` until password is changed.
 
 ```

src/app/components/telegram-login/telegram-login.component.html

@@ -9,8 +9,8 @@
         <app-icon name="lock" [size]="40" />
       </div>
 
-      <h2>{{ 'auth.loginRequired' | translate }}</h2>
-      <p class="login-desc">{{ 'auth.loginDescription' | translate }}</p>
+      <h2>{{ (mode === 'admin' ? 'auth.adminLoginRequired' : 'auth.loginRequired') | translate }}</h2>
+      <p class="login-desc">{{ (mode === 'admin' ? 'auth.adminLoginDescription' : 'auth.loginDescription') | translate }}</p>
 
       @if (status() === 'checking') {
         <div class="login-status checking">
@@ -22,7 +22,7 @@
           <svg class="tg-icon" width="22" height="22" viewBox="0 0 24 24" fill="currentColor">
             <path d="M11.944 0A12 12 0 0 0 0 12a12 12 0 0 0 12 12 12 12 0 0 0 12-12A12 12 0 0 0 12 0a12 12 0 0 0-.056 0zm4.962 7.224c.1-.002.321.023.465.14a.506.506 0 0 1 .171.325c.016.093.036.306.02.472-.18 1.898-.962 6.502-1.36 8.627-.168.9-.499 1.201-.82 1.23-.696.065-1.225-.46-1.9-.902-1.056-.693-1.653-1.124-2.678-1.8-1.185-.78-.417-1.21.258-1.91.177-.184 3.247-2.977 3.307-3.23.007-.032.014-.15-.056-.212s-.174-.041-.249-.024c-.106.024-1.793 1.14-5.061 3.345-.48.33-.913.49-1.302.48-.428-.008-1.252-.241-1.865-.44-.752-.245-1.349-.374-1.297-.789.027-.216.325-.437.893-.663 3.498-1.524 5.83-2.529 6.998-3.014 3.332-1.386 4.025-1.627 4.476-1.635z"/>
           </svg>
-          {{ 'auth.loginWithTelegram' | translate }}
+          {{ (mode === 'admin' ? 'auth.adminLoginWithTelegram' : 'auth.loginWithTelegram') | translate }}
         </button>
 
         <!-- @if (loginUrl()) {
@@ -64,7 +64,7 @@
           }
         </div>
 
-        <p class="login-note">{{ 'auth.loginNote' | translate }}</p>
+        <p class="login-note">{{ (mode === 'admin' ? 'auth.adminLoginNote' : 'auth.loginNote') | translate }}</p>
       }
     </div>
   </div>

src/app/i18n/en.ts

@@ -1154,6 +1154,10 @@ export const en: Translations = {
   auth: {
     loginRequired: 'Login required',
     loginDescription: 'Please log in via Telegram to proceed with your order',
+    adminLoginRequired: 'Admin panel sign-in',
+    adminLoginDescription: 'Sign in through Telegram with an administrator account',
+    adminLoginWithTelegram: 'Sign in as administrator',
+    adminLoginNote: 'The admin panel will open after verification',
     checking: 'Checking...',
     loginWithTelegram: 'Log in with Telegram',
     orScanQr: 'Or scan the QR code',

src/app/i18n/hy.ts

@@ -1154,6 +1154,10 @@ export const hy: Translations = {
   auth: {
     loginRequired: 'Պահանջվում է մուտք',
     loginDescription: 'Պատվերի համար մուտք գործեք Telegram-ով',
+    adminLoginRequired: 'Մուտք կառավարման վահանակ',
+    adminLoginDescription: 'Մուտք գործեք Telegram-ով՝ ադմինիստրատորի հաշվով',
+    adminLoginWithTelegram: 'Մուտք գործել որպես ադմինիստրատոր',
+    adminLoginNote: 'Ստուգումից հետո կբացվի կառավարման վահանակը',
     checking: 'Ստուգում...',
     loginWithTelegram: 'Մուտք Telegram-ով',
     orScanQr: 'Կամ սքանավորեք QR կոդը',

src/app/i18n/ru.ts

@@ -1154,6 +1154,10 @@ export const ru: Translations = {
   auth: {
     loginRequired: 'Требуется авторизация',
     loginDescription: 'Для оформления заказа войдите через Telegram',
+    adminLoginRequired: 'Вход в панель управления',
+    adminLoginDescription: 'Войдите через Telegram с аккаунтом администратора',
+    adminLoginWithTelegram: 'Войти как администратор',
+    adminLoginNote: 'После подтверждения откроется панель управления',
     checking: 'Проверка...',
     loginWithTelegram: 'Войти через Telegram',
     orScanQr: 'Или отсканируйте QR-код',

src/app/i18n/translations.ts

@@ -1153,6 +1153,10 @@ export interface Translations {
   auth: {
     loginRequired: string;
     loginDescription: string;
+    adminLoginRequired: string;
+    adminLoginDescription: string;
+    adminLoginWithTelegram: string;
+    adminLoginNote: string;
     checking: string;
     loginWithTelegram: string;
     orScanQr: string;