Build or refactor a Tool-channel provider (PagerDuty, Opsgenie, future incident/alerting tools) to be endpoint-routed: per-subscriber secrets stored encrypted on a ChannelConnection behind a typed channel endpoint, a stateless provider that resolves routing from channelData at send time, SKIPPED steps when no endpoint exists, and the full API/worker/dashboard/docs/playground surface. Starts with a mandatory provider-docs discovery gate. Use when refactoring Opsgenie to the PagerDuty model, adding a new tool provider, or touching pagerduty_service channel endpoints.