feat: pinned tickets, at hand on the home page and in search

Each person pins up to 20 tickets from the ticket's page («Fijar»). They
show as a strip under the projects on the home page and in the search
palette before typing. Private and without history, like the views of
«my work» (Mongo `pinned_issues`); tickets in the trash or out of reach
are left out, and when the list is full the unreadable ones are dropped
first.

API: GET /api/me/pins, PUT/DELETE /api/issues/{issue}/pin; GraphQL
myPins, pinIssue, unpinIssue and Issue.pinned.

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

libs/api/tracker/application/src/index.ts

@@ -33,6 +33,9 @@ export * from './lib/git/git-payloads';
 export * from './lib/saved-filters/saved-filters';
 export * from './lib/saved-filters/my-views';
 export * from './lib/ports/my-views.repository';
+export * from './lib/saved-filters/pins';
+export * from './lib/ports/pins.repository';
+export * from './lib/pins.service';
 export * from './lib/tracker-application.module';
 export * from './lib/ports/presence.store';
 export * from './lib/presence.service';