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>

libs/web/tracker/domain/src/lib/ports/gateways.ts

@@ -1,4 +1,4 @@
-import { ProjectInsights } from '../models/insights';
+import { PortfolioProject, ProjectInsights } from '../models/insights';
 import { Observable } from 'rxjs';
 import {
   Activity,
@@ -67,6 +67,8 @@ export abstract class ProjectsGateway {
   abstract publicProjects(): Observable<Project[]>;
   abstract project(idOrKey: string): Observable<Project>;
   abstract stats(projectId: string): Observable<ProjectStats>;
+  /** My active projects at a glance. */
+  abstract portfolio(): Observable<PortfolioProject[]>;
   /** The dashboard; with `since`, also what changed after it. */
   abstract insights(
     projectId: string,