* op-node: experimental interop block verification

* op-node: supervisor RPC init

* op-e2e/actions: test interop safety checks

* op-e2e/op-node: test fixes

* op-node: update comments

* op-node: unit-test interop deriver, trigger cross-safe updates on driver step, to poll for supervisor safety changes

* op-node: add more comments, fix flag description

* op-e2e: fix rebase, add missing argument