- Send synthetic `__warm__` payload when no current subtitle exists so the gate can release without waiting for a subtitle event that can't fire while paused
- Visible-overlay readiness accepts `__warm__` once the overlay is content-ready, rejects it otherwise
- Autoplay gate self-retries via scheduled polling when signal target isn't ready, removing reliance on an external flush event
- Skip duplicate desktop notification when overlay or startup sequencer already delivered it
