feat(admin): sprint 19 admin dashboard, routing, i18n

- Add admin dashboard feature (models/gateway/facade/components/page)
- Wire admin/products routes and backoffice coming-soon placeholders
- Add lastPublishedAt to ProjectEditorFacade/state
- Add dashboard i18n keys (en/ru/hy) and docs/ADMIN.md

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

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

@@ -1,6 +1,8 @@
 import { Component, ChangeDetectionStrategy, Input, Injector, Signal, inject, effect, OnDestroy, OnInit } from '@angular/core';
+import { Router } from '@angular/router';
 import { AuthService } from '../../services/auth.service';
 import { AdminAuthService } from '../../core/admin-auth/admin-auth.service';
+import { LanguageService } from '../../services/language.service';
 import { TranslatePipe } from '../../i18n/translate.pipe';
 import { QrLoginEngine } from '../../shared/qr-login/qr-login.engine';
 import { QrLoginAdapter, QrLoginStatus } from '../../shared/qr-login/qr-login.model';
@@ -27,6 +29,8 @@ export class TelegramLoginComponent implements OnInit, OnDestroy {
   private readonly customerAuth = inject(AuthService);
   private readonly adminAuth = inject(AdminAuthService);
   private readonly injector = inject(Injector);
+  private readonly router = inject(Router);
+  private readonly languageService = inject(LanguageService);
 
   private engine!: QrLoginEngine<AuthSession>;
 
@@ -49,7 +53,10 @@ export class TelegramLoginComponent implements OnInit, OnDestroy {
           checkSessionOnce: id => this.adminAuth.checkSessionOnce(id),
           isSessionActive: session => !!session?.active,
           getAppLoginUrl: id => this.adminAuth.getAdminAppLoginUrl(id),
-          onLoginComplete: () => this.adminAuth.onLoginComplete(),
+          onLoginComplete: () => {
+            this.adminAuth.onLoginComplete();
+            void this.router.navigate([this.languageService.currentLanguage(), 'backoffice', 'dashboard']);
+          },
         }
       : {
           createSession: () => this.customerAuth.createWebSession(),