v1.6.3

Fixed

• Scheduled triggers, portal polling, notification emails and the sync check
  no longer cost a process a minute. Each was a Prefect deployment ticking
  every 60 seconds, and every tick was a new Python process importing the whole
  application. On a busy host that took longer than the minute between ticks:
  runs piled up, and the server spent its CPU on imports. They now run as
  sweeps inside the worker's own process, one tick at a time each, staggered
  across the minute. The sync check still starts the syncs as a Prefect run,
  and only when a source is due. The scheduler health check (doctor,
  /admin/system) reads the sweeps' heartbeat from Redis and, separately,
  whether Prefect still completes mcp-connection-sweep (#2213).