feat: a public showcase of each project

A public endpoint sums up a public project for websites: epics with their
dates and progress, the latest releases with the notes of shipped ones,
the sprint under way and open tickets labelled good-first-issue.

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

libs/api/tracker/application/src/lib/projects.service.ts

@@ -1,3 +1,4 @@
+import { GetShowcaseQuery, Showcase } from './queries/get-showcase.query';
 import { Injectable } from '@nestjs/common';
 import { CommandBus, QueryBus } from '@nestjs/cqrs';
 import {
@@ -32,6 +33,11 @@ export class ProjectsService {
     private readonly queryBus: QueryBus,
   ) {}
 
+  /** A public project's roadmap, releases, sprint and good first tickets (no token). */
+  showcase(project: string): Promise<Showcase> {
+    return this.queryBus.execute(new GetShowcaseQuery(project));
+  }
+
   create(
     actorId: string,
     input: {