feat: sprints with burndown and carry-over

Plan sprints with dates and a goal, run one at a time per project, and
put tickets in them from the ticket page. The Sprints tab follows the one
under way with its progress and a burndown in tickets or points against
the ideal line. Closing a sprint sends what was left to the next one or
back to the backlog; the board can be filtered by sprint.

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

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

@@ -0,0 +1,72 @@
+import { Injectable } from '@nestjs/common';
+import { InjectModel } from '@nestjs/mongoose';
+import {
+  FindSprintsRepository,
+  UpsertMaterializedSprintRepository,
+} from '@task-stream/api/tracker/application';
+import { SprintReadModel, SprintStatus } from '@task-stream/api/tracker/domain';
+import { Model } from 'mongoose';
+import { ReadModels, SprintDoc, fromDoc } from './read-model.schemas';
+import { upsertIfNewer } from './upsert-if-newer';
+
+const ORDER: Record<SprintStatus, number> = {
+  [SprintStatus.ACTIVE]: 0,
+  [SprintStatus.PLANNED]: 1,
+  [SprintStatus.CLOSED]: 2,
+};
+
+@Injectable()
+export class MongoFindSprintsRepository extends FindSprintsRepository {
+  constructor(
+    @InjectModel(ReadModels.Sprint) private readonly sprints: Model<SprintDoc>,
+  ) {
+    super();
+  }
+
+  async findById(id: string): Promise<SprintReadModel | null> {
+    const doc = await this.sprints.findById(id).lean<SprintDoc>();
+    return doc ? fromDoc(doc) : null;
+  }
+
+  async findByProject(projectId: string): Promise<SprintReadModel[]> {
+    const docs = await this.sprints.find({ projectId }).lean<SprintDoc[]>();
+    return docs
+      .map(fromDoc)
+      .sort(
+        (a, b) =>
+          ORDER[a.status] - ORDER[b.status] ||
+          (a.status === SprintStatus.CLOSED
+            ? b.startDate.localeCompare(a.startDate)
+            : a.startDate.localeCompare(b.startDate)) ||
+          a.name.localeCompare(b.name),
+      );
+  }
+
+  async findActive(projectId: string): Promise<SprintReadModel | null> {
+    const doc = await this.sprints
+      .findOne({ projectId, status: SprintStatus.ACTIVE })
+      .lean<SprintDoc>();
+    return doc ? fromDoc(doc) : null;
+  }
+}
+
+@Injectable()
+export class MongoUpsertMaterializedSprintRepository extends UpsertMaterializedSprintRepository {
+  constructor(
+    @InjectModel(ReadModels.Sprint) private readonly sprints: Model<SprintDoc>,
+  ) {
+    super();
+  }
+
+  async upsert({
+    id,
+    version,
+    ...fields
+  }: Pick<SprintReadModel, 'id' | 'version'> & Partial<SprintReadModel>) {
+    await upsertIfNewer(this.sprints, id, version, fields);
+  }
+
+  async remove(sprintId: string) {
+    await this.sprints.deleteOne({ _id: sprintId });
+  }
+}