Feature/team confirm reject buttons on project detail

[dcl10]

Description

The project detail page renders proposed teams read-only. Users with the ManageProjects role should be able to confirm or reject each proposed team directly from this page.

Backend behaviour (already implemented):

• PUT /api/projects/{projectId}/teams/{teamId}/confirm — marks the team Confirmed and, if the project is currently Open, transitions it to TeamConfirmed. Requires CanManageProjects policy.
• PUT /api/projects/{projectId}/teams/{teamId}/reject — marks the team Rejected; no side-effect on the project or other teams. Requires CanManageProjects policy.
• Confirming one team does not auto-reject other proposed teams.
• Both actions return the updated TeamDto.
• Both return 409 Conflict if the team is not in Proposed status.

Auth: Buttons should only render when currentUser.role === "ManageProjects".

Frontend pattern to follow: InvitationCard.tsx + app/invitations/actions.ts — server actions that call the API, then revalidatePath, consumed by a client component using useTransition for pending state.

Tasks

• Add confirmTeam(projectId, teamId, token) and rejectTeam(projectId, teamId, token) to frontend/lib/api/projects.ts (return Team type via apiRequest)
• Add confirmTeamAction(projectId, teamId) and rejectTeamAction(projectId, teamId) server actions to frontend/app/projects/[projectId]/actions.ts; revalidate /projects/${projectId} on success
• Extract team rendering into a new client component frontend/app/projects/[projectId]/_TeamCard.tsx; show confirm/reject buttons only when canManage && team.status === "Proposed"; mirror InvitationCard pattern (useTransition, disabled during pending, error display)
• Update frontend/app/projects/[projectId]/page.tsx to fetch currentUser in parallel with project, derive canManage = currentUser.role === "ManageProjects", and pass it to <TeamCard>