Add clarification re L1Admin

Explain how chains in interop cluster have same l1admin to mitigate uni-lateral changes

Author: zainbacchus

pages/stack/interop/explainer.mdx

@@ -40,7 +40,7 @@ This gives the OP Stack an unopinionated and flexible foundation, so chain opera
 ## Superchain interop cluster
 The Superchain builds on top of the interop protocol and implements a single mesh network with complete dependencies. In this model, each blockchain in the Superchain interop cluster would have direct connections to every other blockchain, creating a fully connected mesh network. Compared to a hub and spoke model, this provides the highest level of interoperability, as any blockchain can transact directly with any other.
 
-Each blockchain that is part of the Superchain interop cluster will have the same security model to mitigate the weakest-link scenario and will be managed by Optimism Governance. 
+Each blockchain that is part of the Superchain interop cluster will have the same security model to mitigate the weakest-link scenario. As outlined in the [Standard Rollup Charter](https://gov.optimism.io/t/season-6-standard-rollup-charter-ratification/8135#p-36758-governing-policies-11), chains in the Superchain interop cluster will have the same `L1ProxyAdmin` and must  follow the standard Protocol Upgrade vote procedure to make changes to the Superchain interop cluster, which is the existing path used for governance to exercise changes to the Superchain. 
 
 
 ## New predeploys