feat: move unfinished tickets between releases

- Bulk editing gets «Release…» (open releases or none), and the list
  view a release filter, also reachable from each release («Ver en la
  lista», ?release=).
- Archiving a release asks where its unfinished tickets go, as closing
  a sprint does: ReleaseArchivedEvent carries `moveTo` (an open release
  of the same project, or none) and the saga moves them there; finished
  ones stay. In GraphQL, REST and the MCP's archive_release.
- Chapter 10 lists the next features and the ideas to weigh.

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

libs/api/tracker/domain/src/lib/events/release-archived.event.ts

@@ -1,10 +1,19 @@
 import { AutowiredEvent } from '@task-stream/api/shared/domain';
 import { TrackerEvent } from './tracker.event';
 
-/** The release was archived. */
+/**
+ * The release was archived. Its unfinished tickets move to `moveTo` (an
+ * open release of the same project) or, when null, leave it. Events stored
+ * before `moveTo` existed read as null.
+ */
 @AutowiredEvent
 export class ReleaseArchivedEvent extends TrackerEvent {
-  constructor(actorId: string, releaseId: string, projectId: string) {
+  constructor(
+    actorId: string,
+    releaseId: string,
+    projectId: string,
+    readonly moveTo: string | null = null,
+  ) {
     super(actorId, releaseId, projectId);
   }
 }

libs/api/tracker/domain/src/lib/release/release.ts

@@ -132,9 +132,13 @@ export class Release extends VersionedAggregateRoot implements ReleaseProps {
     );
   }
 
-  archive(actorId: string): void {
+  /** @param moveTo where its unfinished tickets go (null: no release) */
+  archive(actorId: string, moveTo: string | null = null): void {
     if (this.status === ReleaseStatus.ARCHIVED) return;
-    this.apply(new ReleaseArchivedEvent(actorId, this.id, this.projectId));
+    assertThat(moveTo !== this.id, 'A release cannot take its own tickets');
+    this.apply(
+      new ReleaseArchivedEvent(actorId, this.id, this.projectId, moveTo),
+    );
   }
 
   /** Deletes the release (its project was deleted). Idempotent. */