feat: portfolio of all my projects

/cartera (and GraphQL portfolio, REST /api/me/portfolio, MCP
get_portfolio) shows every active project I belong to (not archived, not
as a guest) at a glance: open, overdue, blocked and stuck tickets, the
sprint under way and whether it gets there, planned releases with their
forecast, and the open epics with their progress. It reuses the
dashboard's computations. A release with no tickets now reads «Sin
tickets» instead of «Todo hecho», here and on the dashboard.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/app/app.ts

@@ -41,6 +41,16 @@ import {
           Proyectos
         </a>
       }
+      @if (auth.isAuthenticated()) {
+        <a
+          shellNav
+          class="ts-nav-link"
+          routerLink="/cartera"
+          routerLinkActive="is-active"
+        >
+          Cartera
+        </a>
+      }
       <a
         shellNav
         class="ts-nav-link"