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/find.repositories.ts

@@ -24,6 +24,7 @@ import {
   ProjectRole,
   ProjectStatsReadModel,
   ReleaseProgressReadModel,
+  SprintProgressReadModel,
   ReleaseReadModel,
   ReleaseStatus,
   StatusCategory,
@@ -281,6 +282,37 @@ export class MongoFindIssuesRepository extends FindIssuesRepository {
     });
   }
 
+  async sprintProgress(sprintId: string): Promise<SprintProgressReadModel> {
+    const finished = { $in: ['$statusCategory', FINISHED] };
+    const points = { $ifNull: ['$storyPoints', 0] };
+    const [row] = await this.issues.aggregate<{
+      total: number;
+      finished: number;
+      storyPoints: number;
+      finishedStoryPoints: number;
+    }>([
+      { $match: { 'sprint.id': sprintId } },
+      {
+        $group: {
+          _id: null,
+          total: { $sum: 1 },
+          finished: { $sum: { $cond: [finished, 1, 0] } },
+          storyPoints: { $sum: points },
+          finishedStoryPoints: { $sum: { $cond: [finished, points, 0] } },
+        },
+      },
+    ]);
+    const total = row?.total ?? 0;
+    return {
+      total,
+      finished: row?.finished ?? 0,
+      percent:
+        total === 0 ? 0 : Math.round(((row?.finished ?? 0) / total) * 100),
+      storyPoints: row?.storyPoints ?? 0,
+      finishedStoryPoints: row?.finishedStoryPoints ?? 0,
+    };
+  }
+
   async releaseProgress(releaseId: string): Promise<ReleaseProgressReadModel> {
     const rows = await this.issues.aggregate<{
       _id: { status: string; category: StatusCategory };
@@ -322,6 +354,8 @@ function toMongoFilter(filter: IssueFilter): FilterQuery<IssueDoc> {
     query.labels = { $all: filter.labels.map((l) => l.toLowerCase()) };
   if (filter.releaseId) query['release.id'] = filter.releaseId;
   if (filter.parentId) query['parent.id'] = filter.parentId;
+  if (filter.noSprint) query['sprint'] = null;
+  else if (filter.sprintId) query['sprint.id'] = filter.sprintId;
   if (filter.unassigned) query['assignee'] = null;
   else if (filter.assigneeId) query['assignee.id'] = filter.assigneeId;
   if (filter.search?.trim()) {