feat: a home page with life

Greeting and summary of the day, the coming week, the latest across my
projects, who is online now, the week in numbers (mine and the team's,
with a streak), sprints under way, «Retomar», project cards with their
activity, what to pick up when nothing is mine and first steps for
newcomers. REST (GET /api/me/home), GraphQL (myHome) and MCP
(get_my_week).

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

libs/api/tracker/infrastructure/src/lib/mongo/find.repositories.ts

@@ -614,6 +614,47 @@ export class MongoFindActivityRepository extends FindActivityRepository {
       .lean<ActivityDoc[]>();
     return docs.map(fromDoc);
   }
+
+  async findAcross(
+    projectIds: string[],
+    limit: number,
+  ): Promise<ActivityReadModel[]> {
+    if (!projectIds.length) return [];
+    const docs = await this.activity
+      .find({ projectId: { $in: projectIds } })
+      .sort({ occurredAt: -1 })
+      .limit(limit)
+      .lean<ActivityDoc[]>();
+    return docs.map(fromDoc);
+  }
+
+  async dailyCounts(
+    projectIds: string[],
+    fromDay: string,
+  ): Promise<{ projectId: string; day: string; count: number }[]> {
+    if (!projectIds.length) return [];
+    const rows = await this.activity.aggregate<{
+      _id: { projectId: string; day: string };
+      count: number;
+    }>([
+      {
+        $match: {
+          projectId: { $in: projectIds },
+          occurredAt: { $gte: fromDay },
+        },
+      },
+      {
+        $group: {
+          _id: {
+            projectId: '$projectId',
+            day: { $substrCP: ['$occurredAt', 0, 10] },
+          },
+          count: { $sum: 1 },
+        },
+      },
+    ]);
+    return rows.map((r) => ({ ...r._id, count: r.count }));
+  }
 }
 
 @Injectable()