Add mainnet checkpoint stack: ISO attestation, participant Etherscan surface, and services.

Ship AddressActivityRegistry V1/V2, ISO20022IntakeGateway, Chain138ParticipantSurface,
checkpoint hub contracts, checkpoint-core package, aggregator/indexer/sdk services,
relay profile guards, M00 diamond bridge facet, and OMNL compliance contracts.

Co-authored-by: Cursor <cursoragent@cursor.com>

script/mainnet-checkpoint/RegisterCheckpointExtensions.s.sol

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import {Script, console} from "forge-std/Script.sol";
+import {Chain138MainnetCheckpoint} from "../../contracts/mainnet-checkpoint/Chain138MainnetCheckpoint.sol";
+import {ExtensionIds} from "../../contracts/mainnet-checkpoint/libraries/ExtensionIds.sol";
+import {ICheckpointExtension} from "../../contracts/mainnet-checkpoint/interfaces/ICheckpointExtension.sol";
+
+/// @notice Register deployed extensions on the checkpoint hub (env: EXT_* addresses).
+contract RegisterCheckpointExtensions is Script {
+    function run() external {
+        uint256 pk = vm.envUint("PRIVATE_KEY");
+        address proxy = vm.envAddress("CHAIN138_MAINNET_CHECKPOINT_PROXY");
+        Chain138MainnetCheckpoint hub = Chain138MainnetCheckpoint(proxy);
+
+        vm.startBroadcast(pk);
+        _register(hub, ExtensionIds.METRICS, vm.envAddress("EXT_METRICS"));
+        _register(hub, ExtensionIds.CONTENT_URI, vm.envAddress("EXT_ATTESTATION_URI"));
+        _register(hub, ExtensionIds.RATE_LIMIT, vm.envAddress("EXT_RATE_LIMIT"));
+        _register(hub, ExtensionIds.VALIDATOR_SIG, vm.envAddress("EXT_VALIDATOR_SIG"));
+        _register(hub, ExtensionIds.TOKEN_FILTER, vm.envAddress("EXT_TOKEN_FILTER"));
+        _register(hub, ExtensionIds.CW_LINK, vm.envAddress("EXT_CW_LINK"));
+        _register(hub, ExtensionIds.GOV_TIMELOCK, vm.envAddress("EXT_TIMELOCK"));
+        _register(hub, ExtensionIds.MIRROR_DETAIL, vm.envAddress("EXT_MIRROR_DETAIL"));
+        _register(hub, ExtensionIds.ZK_STATE_ROOT, vm.envAddress("EXT_ZK_STATE_ROOT"));
+        _register(hub, ExtensionIds.PAYMASTER_HINT, vm.envAddress("EXT_PAYMASTER_HINT"));
+        _register(hub, ExtensionIds.L2_ORACLE, vm.envAddress("EXT_L2_ORACLE"));
+        _register(hub, ExtensionIds.BLOCK_ORACLE, vm.envAddress("EXT_BLOCK_ORACLE"));
+        _register(hub, ExtensionIds.MIN_PAYMENT, vm.envAddress("EXT_MIN_PAYMENT"));
+        vm.stopBroadcast();
+    }
+
+    function _register(Chain138MainnetCheckpoint hub, bytes32 id, address module) internal {
+        if (module == address(0)) return;
+        uint32 hooks = ICheckpointExtension(module).HOOK_BEFORE_SUBMIT()
+            | ICheckpointExtension(module).HOOK_AFTER_SUBMIT()
+            | ICheckpointExtension(module).HOOK_ON_CCIP()
+            | ICheckpointExtension(module).HOOK_VERIFY_LEAF();
+        hub.registerExtension(id, module, hooks);
+        console.log("Registered", vm.toString(id), module);
+    }
+}