feat: what is new since my last visit, and turning a comment into a ticket

Opening a ticket notes the visit and answers the one before (issue_visits),
so the page marks others' comments and changes since. A comment can become
a ticket of its own, as a subtask or linked; it remembers where it went.

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

libs/api/tracker/application/src/lib/comments.service.ts

@@ -11,6 +11,7 @@ import { DeleteCommentCommand } from './commands/delete-comment.command';
 import { EditCommentCommand } from './commands/edit-comment.command';
 import { ReactToCommentCommand } from './commands/react-to-comment.command';
 import { MarkDecisionCommand } from './commands/mark-decision.command';
+import { TurnCommentIntoIssueCommand } from './commands/turn-comment-into-issue';
 import { ResolveThreadCommand } from './commands/resolve-thread.command';
 import { ClosePollCommand, VotePollCommand } from './commands/polls';
 import { Page } from './ports/find-issues.repository';
@@ -109,6 +110,25 @@ export class CommentsService {
     );
   }
 
+  /** Makes a ticket of a comment: a subtask of its ticket, or linked to it. */
+  turnIntoIssue(
+    actorId: string,
+    commentId: string,
+    title: string,
+    type: string,
+    asSubtask: boolean,
+  ): Promise<CommandResult> {
+    return this.commands.execute(
+      new TurnCommentIntoIssueCommand(
+        actorId,
+        commentId,
+        title,
+        type,
+        asSubtask,
+      ),
+    );
+  }
+
   /** A ticket's decisions, oldest first. */
   decisions(
     viewerId: string | null,