refactor(api): extract notification procedures

docs/api-router-procedure-support-backlog.md

@@ -16,6 +16,7 @@ Done
 - `insights`
 - `import-export`
 - `chargeability-report`
+- `notification`
 
 Ready next
 - none in the conflict-safe backlog
@@ -24,7 +25,6 @@ Deferred or blocked
 - `assistant-tools`
 - `dashboard`
 - `entitlement`
-- `notification`
 - `resource-read-shared`
 - `resource-summary-read`
 - `user`