Release v0.6.0

• Add log_endpoint config field: forward structured JSON logs to an external
  processor (tcp://, udp://, http://, https://); stdout always receives
  text logs, the endpoint receives JSON in parallel
• Each reconcile emits a phase: start and phase: end record sharing an
  event_id (random 8-byte hex), plus per-change records between them
  (user added, user removed, key added, key removed); the changes
  field on the end record allows processors to suppress no-op notifications
• trigger field (startup / reload / periodic) carried on every reconcile
  log record for filtering by event source
• Endpoint writer is initialised before the startup reconcile so first-deploy
  events are not silently dropped
• Fix: readAuthorizedKeys included the managed-by header comment in key
  comparison, causing every reload to report spurious key changes