feat: release notes

Each release can carry notes in Markdown, written before or after it
ships. A draft is generated from its finished tickets grouped by type, to
edit and copy from the releases page.

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

libs/web/tracker/infrastructure/src/lib/adapters/graphql-collaboration.gateways.ts

@@ -23,6 +23,8 @@ import {
   IssueCommentsDocument,
   PublishReleaseDocument,
   ReleaseBurnupDocument,
+  ReleaseNotesDraftDocument,
+  WriteReleaseNotesDocument,
   ReleasesDocument,
   UpcomingReleasesDocument,
   SearchUsersDocument,
@@ -98,6 +100,21 @@ export class GraphqlReleasesGateway extends ReleasesGateway {
       .query(ReleaseBurnupDocument, { id: releaseId })
       .pipe(map((d) => d.release.burnup));
   }
+
+  notesDraft(releaseId: string): Observable<string> {
+    return this.gql
+      .query(ReleaseNotesDraftDocument, { id: releaseId })
+      .pipe(map((d) => d.release.notesDraft));
+  }
+
+  writeNotes(
+    releaseId: string,
+    notes: string | null,
+  ): Observable<CommandResult> {
+    return this.gql
+      .mutate(WriteReleaseNotesDocument, { releaseId, notes })
+      .pipe(map((d) => toCommandResult(d.writeReleaseNotes)));
+  }
 }
 
 @Injectable()