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>

apps/api/e2e/tracker.e2e-spec.ts

@@ -1414,5 +1414,28 @@ describe('task-stream (e2e)', () => {
       { k: key },
     );
     expect(project.insights.risks.overdueCount).toBe(1);
+
+    // What changed since a moment, and what the backlog lacks.
+    const since = new Date(Date.now() - 60_000).toISOString();
+    const later = await rest(
+      'token-ana',
+      'GET',
+      `/projects/${key}/insights?since=${encodeURIComponent(since)}`,
+    );
+    expect(later.body['changes']).toMatchObject({ since, createdCount: 2 });
+    expect(later.body['backlog']).toMatchObject({
+      open: 2,
+      unestimated: 2,
+      unassigned: 2,
+    });
+    expect(
+      later.body['team'].map((t: { user: { id: string } }) => t.user.id),
+    ).toContain('101');
+    const unestimated = await rest(
+      'token-ana',
+      'GET',
+      `/projects/${key}/issues?noEstimate=true&noArea=true`,
+    );
+    expect(unestimated.body['total']).toBe(2);
   });
 });