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/ReenableCheckpointExtensions.s.sol

@@ -0,0 +1,21 @@
+// 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";
+
+/// @notice Re-enable extensions after hub v3 + token filter replace (env: EXT_VALIDATOR_SIG optional sanity).
+contract ReenableCheckpointExtensions is Script {
+    function run() external {
+        uint256 pk = vm.envUint("PRIVATE_KEY");
+        Chain138MainnetCheckpoint hub = Chain138MainnetCheckpoint(vm.envAddress("CHAIN138_MAINNET_CHECKPOINT_PROXY"));
+
+        vm.startBroadcast(pk);
+        hub.setExtensionActive(ExtensionIds.VALIDATOR_SIG, true);
+        console.log("VALIDATOR_SIG active");
+        hub.setExtensionActive(ExtensionIds.TOKEN_FILTER, true);
+        console.log("TOKEN_FILTER active");
+        vm.stopBroadcast();
+    }
+}