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 }>(),
   },
 });
 

libs/web/tracker/application/src/lib/facades/insights.facade.ts

@@ -14,9 +14,12 @@ export class InsightsFacade {
   readonly loaded = this.store.loaded;
   readonly error = this.store.error;
 
-  /** Loads the project's reading and keeps it up to date. */
-  open(projectId: string): void {
-    this.dispatch.opened({ projectId });
+  /**
+   * Loads the project's reading and keeps it up to date; with `since` (my
+   * last visit), it also tells what changed after it.
+   */
+  open(projectId: string, since: string | null = null): void {
+    this.dispatch.opened({ projectId, since });
   }
 }
 

libs/web/tracker/application/src/lib/stores/insights.store.ts

@@ -58,7 +58,7 @@ export const InsightsStore = signalStore(
             debounceTime(800),
             startWith(null),
             switchMap(() =>
-              projects.insights(payload.projectId).pipe(
+              projects.insights(payload.projectId, payload.since).pipe(
                 mapResponse({
                   next: (insights) => insightsApiEvents.loaded(insights),
                   error: (error) =>