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/web/tracker/domain/src/lib/models/workflow.ts

@@ -51,12 +51,21 @@ export interface StatusTransitions {
   to: string[];
 }
 
+/** What a new ticket of a type starts with. */
+export interface IssueTemplate {
+  /** Used when the ticket comes without a description. */
+  description: string | null;
+  /** Steps added to every new ticket of the type. */
+  checklist: string[];
+}
+
 export interface IssueTypeOption {
   id: string;
   name: string;
   icon: string;
   color: string;
   archived: boolean;
+  template?: IssueTemplate | null;
 }
 
 export interface AreaOption {