feat: templates per ticket type

Each ticket type can carry a starting description and a checklist, edited
in the project settings. New tickets of that type get the description
when they come without one and always get the checklist; the new ticket
form says what the template will add.

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

libs/api/tracker/presenters/src/lib/http/dto/responses.dto.ts

@@ -53,6 +53,11 @@ export class StatusTransitionsDto {
   to!: string[];
 }
 
+export class IssueTemplateDto {
+  @ApiProperty({ type: String, nullable: true }) description!: string | null;
+  @ApiProperty({ type: [String] }) checklist!: string[];
+}
+
 export class IssueTypeOptionDto {
   @ApiProperty({ example: 'BUG' }) id!: string;
   @ApiProperty({ example: 'Bug' }) name!: string;
@@ -60,6 +65,11 @@ export class IssueTypeOptionDto {
   @ApiProperty({ enum: SETTING_COLORS, enumName: 'SettingColor' })
   color!: string;
   @ApiProperty() archived!: boolean;
+  @ApiPropertyOptional({
+    type: IssueTemplateDto,
+    description: 'What a new ticket of the type starts with',
+  })
+  template?: IssueTemplateDto;
 }
 
 export class AreaOptionDto {