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/presenters/src/lib/http/dto/responses.dto.ts

@@ -628,6 +628,10 @@ export class CommentPollDto {
   winner!: number | null;
 }
 
+export class CommentSpawnDto {
+  @ApiProperty() id!: string;
+  @ApiProperty({ example: 'WEB-45' }) key!: string;
+}
 export class CommentDto {
   @ApiProperty({ format: 'uuid' }) id!: string;
   @ApiProperty({ format: 'uuid' }) issueId!: string;
@@ -679,6 +683,11 @@ export class CommentDto {
   resolvedBy!: UserRefDto | null;
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
   resolvedAt!: string | null;
+  @ApiProperty({
+    type: () => [CommentSpawnDto],
+    description: 'Tickets made from it («Convertir en ticket»), oldest first',
+  })
+  spawned!: CommentSpawnDto[];
   @ApiProperty({ format: 'date-time' }) createdAt!: string;
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
   editedAt!: string | null;
@@ -1447,6 +1456,16 @@ export class IssueReminderDto {
   @ApiProperty({ type: String, nullable: true }) note!: string | null;
 }
 
+export class IssueVisitDto {
+  @ApiProperty({
+    type: String,
+    format: 'date-time',
+    nullable: true,
+    description: 'My visit before this one (null: first time)',
+  })
+  previousVisit!: string | null;
+}
+
 export class ReminderOnIssueDto {
   @ApiProperty({ type: IssueReminderDto }) reminder!: IssueReminderDto;
   @ApiProperty({ type: () => IssueDto }) issue!: IssueDto;