feat: dashboard reads the sprint, the risks, aging and bottlenecks

A new projectInsights reading (GraphQL Project.insights, REST
/projects/{project}/insights, MCP get_project_insights), computed by pure
functions over the read model and the timeline:
- the sprint under way: days left, points done, pace against what is
  needed and whether it gets there;
- tickets at risk: overdue, due within a week, blocked by an open ticket
  and stuck (7 days or more in an in-progress or QA status);
- aging of the work under way against the p85 cycle time;
- average days in each in-progress and QA status, with WIP limits.
The dashboard shows them in four new panels, reloaded on every change.

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

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

@@ -1,3 +1,4 @@
+import { ProjectInsights } from '../models/insights';
 import { Observable } from 'rxjs';
 import {
   Activity,
@@ -63,6 +64,8 @@ export abstract class ProjectsGateway {
   abstract publicProjects(): Observable<Project[]>;
   abstract project(idOrKey: string): Observable<Project>;
   abstract stats(projectId: string): Observable<ProjectStats>;
+  /** Sprint under way, risks, aging and bottlenecks (the dashboard). */
+  abstract insights(projectId: string): Observable<ProjectInsights>;
   /** Statistics of the last `days` days. */
   abstract analytics(
     projectId: string,