feat: close stub-page gaps - profile login/logout, admin Reports/Settings, Help/Docs links

Sprint A: storefront header profile control (login/logout only, no menu),
wired to existing customer Telegram auth (AuthService).

Sprint B: backoffice/reports page, reuses AdminAnalyticsFacade (Sales,
Top Products, Marketplace Health cards + CSV export).

Sprint C: backoffice/settings page, admin UI density preference
(comfortable/compact), localStorage-persisted, applied to app-table
across all admin list pages.

Sprint D: admin bottom-nav Help -> mailto using existing supportEmail,
Documentation -> external link via new TenantConfig.documentationUrl.
AdminNavLink gains externalHref for non-routerLink nav entries.

Docs: docs/GLOBAL-SPRINT-PLAN.md tracks the full sprint breakdown.
docs/COMING-SOON-AUDIT.md removed, folded into docs/KNOWN-ISSUES.md.
docs/BACKEND.md updated with the new documentationUrl bootstrap field.

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

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

@@ -0,0 +1,14 @@
+<section class="admin-settings-page">
+  <div class="settings-card">
+    <h2>{{ 'adminSettings.density' | translate }}</h2>
+    <p class="settings-explain">{{ 'adminSettings.densityExplain' | translate }}</p>
+    <label class="toggle-row">
+      <app-toggle
+        [ngModel]="preferences.density() === 'compact'"
+        (ngModelChange)="onCompactToggle($event)"
+        [ariaLabel]="'adminSettings.densityCompact' | translate"
+      />
+      <span>{{ 'adminSettings.densityCompact' | translate }}</span>
+    </label>
+  </div>
+</section>