Gitea #6 (parts 1+2): admin.listUsers now batch-fetches email/name from
Clerk (users only stored the Clerk userId locally, everything else
lives in Clerk) instead of showing a bare userId. Adds
admin.startTeamConversation, which lazily creates a "PawFeed Team"
system Pet under ADMIN_OWNER_ID and reuses the existing pet-to-pet
Conversation/Message model instead of a parallel admin-inbox system —
the admin panel switches ActivePet to Team and opens the ordinary
/messages/[conversationId] thread, so no new UI is needed on the
recipient's side.
Known limitation: only the literal ADMIN_OWNER_ID account can act as
Team, since assertPetOwnership requires an exact owner match.
Extending this to every AdminRole holder is left for a follow-up.
Part 3 (GDPR Art. 15 data export) is deliberately not included —
research only per the issue's own "erst prüfen dann bauen" note.