feat: statuses and ticket types take any colour from a colour picker

Settings shows a native colour picker (the palette as suggestions)
instead of the list of eleven names. The API takes a palette name, as
before, or any #rrggbb; picking a palette colour still saves its name,
so it keeps its hand-made dark version. A free colour gets one variant
per theme, computed with the `color` library (moved towards white or
black until it contrasts 3:1 with the surface) and applied with
light-dark(): a pale yellow darkens on white, a navy lightens on dark.

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

libs/web/tracker/infrastructure/src/lib/graphql/generated.ts

@@ -231,6 +231,7 @@ export type IssueTemplateInput = {
 
 export type IssueTypeOptionInput = {
   archived?: boolean;
+  /** A palette colour (follows the theme) or #rrggbb */
   color: string;
   icon: string;
   id: string;
@@ -422,6 +423,7 @@ export type UpdateWebhookInput = {
 export type WorkflowStatusInput = {
   archived?: boolean;
   category: StatusCategory;
+  /** A palette colour (follows the theme) or #rrggbb */
   color: string;
   id: string;
   name: string;