Normalize send_message recipients so name@team values resolve to member names, preventing false recipient-not-found fallbacks into duplicate delegation paths. Also add delegation consistency coverage and split teammate runtime helpers for clearer spawn and parent-context handling.
Validate sender/owner/team flows more strictly, fail fast on invalid model overrides, and cancel failed launches to prevent orphaned background tasks while expanding functional coverage for these paths.
Port team lifecycle, teammate runtime, inbox messaging, and team-scoped task flows into built-in tools so multi-agent coordination works natively without external server dependencies.
