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/web/tracker/application/src/lib/events/insights.events.ts

@@ -5,7 +5,8 @@ import { ProjectInsights } from '@task-stream/web/tracker/domain';
 export const insightsPageEvents = eventGroup({
   source: 'Dashboard Page',
   events: {
-    opened: type<{ projectId: string }>(),
+    /** `since`: my last visit, to tell what changed after it. */
+    opened: type<{ projectId: string; since: string | null }>(),
   },
 });