Review round 4 (Codex gpt-5.6-terra, HIGH): relying on the flow
context alone can leave first setup ownerless. seed_setup_admin gains
an owner_ids tier: when no persisted copy and no context user exist,
every HA owner account is seeded (owners can already do everything in
HA — no privilege escalation). __init__ resolves owners via
hass.auth.async_get_users on both setup paths; conftest's hass gains
the auth surface. Tests: owner fallback seeds only owners, context
user still wins over owners, owner_ids argument validation. Suite:
910 passed.