Add governed reusable pipelines and triggers

README.md

@@ -63,6 +63,24 @@ pipeline revision, and can atomically publish a complete result through
 truncated; larger asynchronous and artifact-backed execution belongs to a
 subsequent runner slice.
 
+## Governed Definitions And Automation
+
+Pipelines can be complete flows or reusable templates at system, tenant,
+group, or user scope. Templates never run directly. A permitted consumer
+derives a new definition that pins the source revision and content hash and
+records the effective Policy decision and ancestor limits. Inherited
+definitions remain read-only; lower scopes may narrow, but not broaden,
+execution, reuse, inheritance, or automation permissions.
+
+Complete active flows support explicit user/API starts, administrative
+backfills, one-time schedules, interval schedules, and exact-match platform
+events. Trigger deliveries are durable and idempotent. They pin the pipeline
+revision and a least-privilege scope grant, then ask Access to rebuild the
+owner's current principal before every run. Revoked memberships or reduced
+permissions block the delivery before source access or output publication.
+Confidential and restricted events are not accepted through the direct
+ingress; those require Core's transactional event bridge.
+
 ## Development
 
 ```bash