feat: bulk edit tickets

Select several tickets in the backlog and change their status, assignee,
sprint, priority or labels at once. Each ticket goes through the normal
rules and may refuse on its own; the result says which did.

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

libs/api/tracker/presenters/src/lib/graphql/issue.resolver.ts

@@ -24,6 +24,7 @@ import {
 } from '@task-stream/api/tracker/domain';
 import {
   AddChecklistItemInput,
+  BulkUpdateIssuesInput,
   ChangeIssueStatusInput,
   CreateIssueInput,
   IssueFilterInput,
@@ -34,8 +35,10 @@ import {
 } from './inputs';
 import { withoutNulls } from '../common/issue-input';
 import { viewerOf } from '../common/viewer';
+import { toBulkChange } from '../common/bulk';
 import {
   ActivityGql,
+  BulkResultGql,
   CommandResultGql,
   CommentPageGql,
   EpicGql,
@@ -280,6 +283,21 @@ export class IssueResolver {
     );
   }
 
+  @Mutation(() => BulkResultGql, {
+    description:
+      'The same change on up to 100 tickets; each goes through the normal rules and may refuse on its own',
+  })
+  bulkUpdateIssues(
+    @CurrentUser() me: User,
+    @Args('input') input: BulkUpdateIssuesInput,
+  ) {
+    return this.issuesService.bulkUpdate(
+      me.id,
+      input.issueIds,
+      toBulkChange(input),
+    );
+  }
+
   @Mutation(() => CommandResultGql, {
     description: "Add a step to a ticket's checklist",
   })