feat: hourglass (task-based AVS framework) (#1534)

**Motivation:**

We need to migrate the hourglass core contracts from
https://github.com/Layr-Labs/hourglass-monorepo/tree/master/contracts.

This is due to the following reasons:
* Better security posture of the core contracts repository
* Automatic support of Zeus for contract upgrades
* Easier maintainability along with other core contracts which will be
governed by the protocol council.

**Modifications:**

* TaskMailbox and interface
* Extensive unit tests for the TaskMailbox (with appropriate Mock
contracts)
* Updated bindings (Including stale bindings from Multichain)
* Smart contract documentation for the TaskMailbox

**Result:**

The Hourglass core contract migration.

Author: 0xrajath

docs/avs/task/TaskMailbox.md

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.27;
+
+import {ITaskMailbox} from "../../interfaces/ITaskMailbox.sol";
+import {IKeyRegistrarTypes} from "../../interfaces/IKeyRegistrar.sol";
+
+/**
+ * @title TaskMailboxStorage
+ * @author Layr Labs, Inc.
+ * @notice Storage contract for the TaskMailbox contract.
+ */
+abstract contract TaskMailboxStorage is ITaskMailbox {
+    /// @notice Equivalent to 100%, but in basis points.
+    uint16 internal constant ONE_HUNDRED_IN_BIPS = 10_000;
+
+    /// @notice Immutable BN254 certificate verifier
+    address public immutable BN254_CERTIFICATE_VERIFIER;
+
+    /// @notice Immutable ECDSA certificate verifier
+    address public immutable ECDSA_CERTIFICATE_VERIFIER;
+
+    /// @notice Global counter for tasks created across the TaskMailbox
+    uint256 internal _globalTaskCount;
+
+    /// @notice Mapping from task hash to task details
+    mapping(bytes32 taskHash => Task task) internal _tasks;
+
+    /// @notice Mapping to track registered executor operator sets by their keys
+    mapping(bytes32 operatorSetKey => bool isRegistered) public isExecutorOperatorSetRegistered;
+
+    /// @notice Mapping from executor operator set key to its task configuration
+    mapping(bytes32 operatorSetKey => ExecutorOperatorSetTaskConfig config) internal _executorOperatorSetTaskConfigs;
+
+    /// @notice The fee split percentage in basis points (0-10000)
+    uint16 public feeSplit;
+
+    /// @notice The address that receives the fee split
+    address public feeSplitCollector;
+
+    /**
+     * @notice Constructor for TaskMailboxStorage
+     * @param _bn254CertificateVerifier Address of the BN254 certificate verifier
+     * @param _ecdsaCertificateVerifier Address of the ECDSA certificate verifier
+     */
+    constructor(address _bn254CertificateVerifier, address _ecdsaCertificateVerifier) {
+        BN254_CERTIFICATE_VERIFIER = _bn254CertificateVerifier;
+        ECDSA_CERTIFICATE_VERIFIER = _ecdsaCertificateVerifier;
+    }
+
+    /**
+     * @dev This empty reserved space is put in place to allow future versions to add new
+     * variables without shifting down storage in the inheritance chain.
+     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
+     */
+    uint256[45] private __gap;
+}

pkg/bindings/IAVSTaskHook/binding.go

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.27;
+
+import {ITaskMailboxTypes} from "./ITaskMailbox.sol";
+import {OperatorSet} from "../libraries/OperatorSetLib.sol";
+
+/**
+ * @title IAVSTaskHook
+ * @author Layr Labs, Inc.
+ * @notice Interface for AVS-specific task lifecycle hooks.
+ * @dev This interface allows AVSs to implement custom validation logic for tasks.
+ */
+interface IAVSTaskHook {
+    /**
+     * @notice Validates a task before it is created
+     * @param caller Address that is creating the task
+     * @param taskParams Task parameters
+     * @dev This function should revert if the task should not be created
+     */
+    function validatePreTaskCreation(address caller, ITaskMailboxTypes.TaskParams memory taskParams) external view;
+
+    /**
+     * @notice Handles a task after it is created
+     * @param taskHash Unique identifier of the task
+     * @dev This function can be used to perform additional validation or update AVS-specific state
+     */
+    function handlePostTaskCreation(
+        bytes32 taskHash
+    ) external;
+
+    /**
+     * @notice Validates a task before it is submitted for verification
+     * @param caller Address that is submitting the result
+     * @param taskHash Unique identifier of the task
+     * @param cert Certificate proving the validity of the result
+     * @param result Task execution result data
+     * @dev This function should revert if the task should not be verified
+     */
+    function validatePreTaskResultSubmission(
+        address caller,
+        bytes32 taskHash,
+        bytes memory cert,
+        bytes memory result
+    ) external view;
+
+    /**
+     * @notice Handles a task result submission
+     * @param taskHash Unique identifier of the task
+     * @dev This function can be used to perform additional validation or update AVS-specific state
+     */
+    function handlePostTaskResultSubmission(
+        bytes32 taskHash
+    ) external;
+
+    /**
+     * @notice Calculates the fee for a task payload against a specific fee market
+     * @param taskParams The task parameters
+     * @return The fee for the task
+     */
+    function calculateTaskFee(
+        ITaskMailboxTypes.TaskParams memory taskParams
+    ) external view returns (uint96);
+}