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/application/src/lib/event-handlers/activity-summary.ts

@@ -28,6 +28,12 @@ import {
   ReleaseCreatedEvent,
   ReleaseShippedEvent,
   ReleaseUpdatedEvent,
+  IssueSprintChangedEvent,
+  SprintClosedEvent,
+  SprintCreatedEvent,
+  SprintDeletedEvent,
+  SprintStartedEvent,
+  SprintUpdatedEvent,
   TrackerEvent,
 } from '@task-stream/api/tracker/domain';
 
@@ -37,6 +43,8 @@ export interface SummaryContext {
   issueKey: string;
   projectKey: string;
   releaseName: string;
+  /** '' when unknown (e.g. the sprint was deleted). */
+  sprintName: string;
   /** The project's workflow: names of statuses and types. */
   workflow: ProjectWorkflow;
 }
@@ -146,6 +154,12 @@ export function describeEvent(
   if (event instanceof IssueAttachmentRemovedEvent)
     return `${actor} quitó el adjunto ${event.fileName} de ${issueKey}`;
 
+  if (event instanceof IssueSprintChangedEvent) {
+    const sprint = ctx.sprintName ? `el sprint ${ctx.sprintName}` : 'un sprint';
+    return event.sprintId
+      ? `${actor} metió ${issueKey} en ${sprint}`
+      : `${actor} sacó ${issueKey} de ${sprint}`;
+  }
   if (event instanceof IssueParentChangedEvent) {
     return event.parentKey
       ? `${actor} colocó ${issueKey} bajo ${event.parentKey}`
@@ -178,5 +192,20 @@ export function describeEvent(
     return `${actor} publicó la release ${ctx.releaseName} 🚀`;
   if (event instanceof ReleaseArchivedEvent)
     return `${actor} archivó la release ${ctx.releaseName}`;
+  const sprint = ctx.sprintName || 'un sprint';
+  if (event instanceof SprintCreatedEvent)
+    return `${actor} planificó el sprint ${event.sprint.name}`;
+  if (event instanceof SprintUpdatedEvent)
+    return `${actor} actualizó el sprint ${sprint}`;
+  if (event instanceof SprintStartedEvent)
+    return `${actor} empezó el sprint ${sprint} 🏁`;
+  if (event instanceof SprintClosedEvent) {
+    const left = event.unfinishedIssues
+      ? `; ${event.unfinishedIssues} ticket(s) sin terminar pasan ${event.carryOverTo ? 'al siguiente sprint' : 'al backlog'}`
+      : '';
+    return `${actor} cerró el sprint ${sprint}${left}`;
+  }
+  if (event instanceof SprintDeletedEvent)
+    return `${actor} borró el sprint ${sprint}`;
   return `${actor}: ${event.constructor.name}`;
 }