feat: guest role for clients and outsiders

A project member can be a GUEST. In a private project a guest only sees
the tickets they take part in (opened, assigned or followed): every other
ticket answers 404, also in my work, realtime changes, blockers and
linked tickets, and project-wide views (activity, statistics, dashboard,
releases, sprints, epics, trash) answer 403. Guests open tickets without
assigning or planning them, and comment, attach, follow and vote on their
own; they change nothing else. In a public project they see what anyone
does. The web gives them only Tablero, Lista and Miembros and loads none
of the project-wide data.

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

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

@@ -272,7 +272,7 @@ export type ProjectMemberInput = {
   userId: string;
 };
 
-export type ProjectRole = 'ADMIN' | 'MEMBER' | 'OWNER' | 'VIEWER';
+export type ProjectRole = 'ADMIN' | 'GUEST' | 'MEMBER' | 'OWNER' | 'VIEWER';
 
 /** The whole configuration (replaces the previous one). Statuses go in board order. */
 export type ProjectSettingsInput = {