feat: Phase 4 frontend - Integrations backoffice section (mock-gateway backed)

New core/integrations (Connector/DeadLetterEntry models + gateway/token)
and features/admin/integrations (facade + page: connector table with
status/lag/errors/backlog/unmatched, pause/resume). Seeded empty per
Sprint 0.1's "no fixed partner list" decision - the section is ready to
populate the moment the first real connector is onboarded against
docs/backend/PHASE-4-CONNECTOR-FRAMEWORK-CONTRACT.md §7. New /backoffice/
integrations route + nav entry, nav i18n key in all 3 languages.

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

src/app/features/admin/integrations/facade/admin-integrations.facade.ts

@@ -0,0 +1,28 @@
+import { Injectable, inject, signal } from '@angular/core';
+import { take } from 'rxjs/operators';
+import { Connector } from '../../../../core/integrations/models/connector.model';
+import { CONNECTOR_GATEWAY } from '../../../../core/integrations/services/connector-gateway.token';
+
+@Injectable({ providedIn: 'root' })
+export class AdminIntegrationsFacade {
+  private readonly gateway = inject(CONNECTOR_GATEWAY);
+
+  readonly connectors = signal<Connector[]>([]);
+  readonly loading = signal(false);
+
+  load(): void {
+    this.loading.set(true);
+    this.gateway.loadConnectors().pipe(take(1)).subscribe(items => {
+      this.connectors.set(items);
+      this.loading.set(false);
+    });
+  }
+
+  pause(id: string): void {
+    this.gateway.pause(id).pipe(take(1)).subscribe(() => this.load());
+  }
+
+  resume(id: string): void {
+    this.gateway.resume(id).pipe(take(1)).subscribe(() => this.load());
+  }
+}

src/app/features/admin/integrations/pages/admin-integrations-page.component.html

@@ -0,0 +1,38 @@
+<div class="integrations-page">
+  <header>
+    <h1>Integrations</h1>
+    <p>External marketplace connectors, payment providers, FX sources, messaging. No fixed partner list - connectors onboard as partners arrive (docs/backend/PHASE-4-CONNECTOR-FRAMEWORK-CONTRACT.md).</p>
+  </header>
+
+  @if (facade.connectors().length === 0 && !facade.loading()) {
+    <app-empty-state title="No connectors yet" description="Onboard the first partner connector to see it here." />
+  } @else {
+    <table class="integrations-page__table">
+      <thead>
+        <tr>
+          <th>Provider</th><th>Status</th><th>Last success</th><th>Lag</th><th>Errors</th><th>Backlog</th><th>Unmatched</th><th></th>
+        </tr>
+      </thead>
+      <tbody>
+        @for (c of facade.connectors(); track c.id) {
+          <tr>
+            <td>{{ c.provider }}</td>
+            <td><app-badge [variant]="c.status === 'active' ? 'success' : c.status === 'error' ? 'danger' : 'neutral'">{{ c.status }}</app-badge></td>
+            <td>{{ c.lastSuccessAt || '-' }}</td>
+            <td>{{ c.lagSeconds ?? '-' }}s</td>
+            <td>{{ c.errorCount }}</td>
+            <td>{{ c.backlogCount }}</td>
+            <td>{{ c.unmatchedCount }}</td>
+            <td>
+              @if (c.status === 'active') {
+                <app-button variant="secondary" (click)="facade.pause(c.id)">Pause</app-button>
+              } @else {
+                <app-button variant="secondary" (click)="facade.resume(c.id)">Resume</app-button>
+              }
+            </td>
+          </tr>
+        }
+      </tbody>
+    </table>
+  }
+</div>

src/app/features/admin/integrations/pages/admin-integrations-page.component.scss

@@ -0,0 +1,16 @@
+.integrations-page {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+
+  &__table {
+    width: 100%;
+    border-collapse: collapse;
+
+    th, td {
+      text-align: left;
+      padding: 8px 12px;
+      border-bottom: 1px solid var(--border-color);
+    }
+  }
+}

src/app/features/admin/integrations/pages/admin-integrations-page.component.ts

@@ -0,0 +1,22 @@
+import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
+import { CommonModule } from '@angular/common';
+import { AdminIntegrationsFacade } from '../facade/admin-integrations.facade';
+import { BadgeComponent } from '../../../../shared/ui/badge/badge.component';
+import { ButtonComponent } from '../../../../shared/ui/button/button.component';
+import { EmptyStateComponent } from '../../../../shared/ui/empty-state/empty-state.component';
+
+@Component({
+  selector: 'app-admin-integrations-page',
+  standalone: true,
+  imports: [CommonModule, BadgeComponent, ButtonComponent, EmptyStateComponent],
+  templateUrl: './admin-integrations-page.component.html',
+  styleUrls: ['./admin-integrations-page.component.scss'],
+  changeDetection: ChangeDetectionStrategy.OnPush
+})
+export class AdminIntegrationsPageComponent {
+  readonly facade = inject(AdminIntegrationsFacade);
+
+  constructor() {
+    this.facade.load();
+  }
+}

src/app/features/admin/shell/admin-nav.model.ts

@@ -39,6 +39,7 @@ export const ADMIN_NAV_PRIMARY: AdminNavEntry[] = [
   { type: 'link', id: 'transactions', icon: 'creditCard', labelKey: 'adminShell.nav.transactions', path: ['transactions'] },
   { type: 'link', id: 'moderation', icon: 'star', labelKey: 'adminShell.nav.moderation', path: ['moderation'] },
   { type: 'link', id: 'notifications', icon: 'bell', labelKey: 'adminShell.nav.notifications', path: ['notifications'] },
+  { type: 'link', id: 'integrations', icon: 'network', labelKey: 'adminShell.nav.integrations', path: ['integrations'] },
   { type: 'link', id: 'reports', icon: 'chartBar', labelKey: 'adminShell.nav.reports', path: ['reports'] },
   { type: 'group', labelKey: 'adminShell.nav.partnersGroup' },
   { type: 'link', id: 'seller-management', icon: 'store', labelKey: 'adminShell.nav.sellerManagement', path: ['partners', 'seller-management'] },