feat: teams within a project

Projects keep teams of members in their settings (settings.teams; people
outside the project are dropped, teams are archived, not removed; absent
when saving means unchanged). Tickets go to a team (`team`, also filtered
in the list and in MCP search_issues), and a comment mentioning
@[Frontend](team-FRONT) tells each of its members. Settings has the teams
with their members, the ticket a «Equipo» select, the list a team filter,
and «@» offers the teams after the people.

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

libs/api/tracker/application/src/lib/issues.service.ts

@@ -350,6 +350,7 @@ export class IssuesService {
       title: `${issue.title} (copia)`.slice(0, 255),
       description: issue.description,
       area: issue.area,
+      team: issue.team,
       priority: issue.priority,
       labels: issue.labels,
       figmaUrl: issue.figmaUrl,