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/components/header/header.component.html

@@ -80,6 +80,19 @@
         </a>
         }
 
+        <!-- Profile (login/logout only) -->
+        @if (headerConfig().showProfile) {
+          @if (isAuthenticated()) {
+            <button type="button" class="platform-ux-btn" (click)="logout()" [attr.aria-label]="'header.logout' | translate">
+              <app-icon name="logOut" [size]="16" class="platform-ux-icon" />
+            </button>
+          } @else {
+            <button type="button" class="platform-ux-btn" (click)="login()" [attr.aria-label]="'header.login' | translate">
+              <app-icon name="user" [size]="16" class="platform-ux-icon" />
+            </button>
+          }
+        }
+
         <!-- Region Selector (desktop only) -->
         @if (headerConfig().showRegion) {
         <div class="platform-region-selector platform-lang-desktop">
@@ -147,4 +160,6 @@
       </div>
     </div>
 
+  <app-telegram-login />
+