A team's BYOK models (rows in LiteLLM_ProxyModelTable with model_info.team_id set)
were left orphaned when the team was deleted; they lingered in the database and kept
showing on the Models + Endpoints page. delete_team now removes them via a new
delete_team_models helper that deletes the rows in one transaction and syncs the
in-memory router only after that transaction commits, run before the team rows are
deleted so a mid-flight failure never leaves the team gone with its models orphaned
