feat: dashboard forecasts releases, tells what changed and weighs the load

The insights reading grows (GraphQL insights(since:), REST ?since=, MCP):
- planned releases with a likely (p50) and safe (p85) finish date from a
  Monte Carlo over the last six weeks of finished work, one after another,
  and a verdict against their target;
- with `since` (the viewer's last visit, kept in the browser): tickets
  created, finished and sent back from QA, and their mentions;
- each person's open points against what they closed per sprint lately;
- open tickets without estimate, area or assignee, or untouched for 90
  days, each count opening the list filtered (new noEstimate, noArea and
  updatedBefore filters).

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

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

@@ -323,13 +323,14 @@ export class ProjectsService {
   }
 
   /** Statistics over the last `days` days (created vs resolved, flow, times, QA). */
-  /** Sprint under way, risks, aging and bottlenecks, for the dashboard. */
+  /** The dashboard's reading; with `since`, what changed after it too. */
   insights(
     viewerId: string | null,
     projectId: string,
+    since: Date | null = null,
   ): Promise<ProjectInsightsReadModel> {
     return this.queryBus.execute(
-      new GetProjectInsightsQuery(viewerId, projectId),
+      new GetProjectInsightsQuery(viewerId, projectId, since),
     );
   }