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

@@ -0,0 +1,18 @@
+import { type } from '@ngrx/signals';
+import { eventGroup } from '@ngrx/signals/events';
+import { ProjectInsights } from '@task-stream/web/tracker/domain';
+
+export const insightsPageEvents = eventGroup({
+  source: 'Dashboard Page',
+  events: {
+    opened: type<{ projectId: string }>(),
+  },
+});
+
+export const insightsApiEvents = eventGroup({
+  source: 'Insights API',
+  events: {
+    loaded: type<ProjectInsights>(),
+    loadFailed: type<string>(),
+  },
+});