Initial Meridian Protocol implementation

- Complete MeridianToken standard with compliance & reserve checks
- Multi-custodian ReserveAggregator supporting bank/crypto/fund admin
- Comprehensive Compliance engine with KYC/AML/sanctions
- Full interface definitions and deployment scripts
- Test suite for core functionality
- Ready for GBP launch with Anchorage custody integration

contracts/interfaces/IReserveAggregator.sol

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+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+/**
+ * @title IReserveAggregator
+ * @dev Interface for reserve aggregation from multiple custodians
+ */
+interface IReserveAggregator {
+    struct CustodianInfo {
+        string name;
+        address oracle;
+        uint256 lastUpdateTime;
+        uint256 heartbeat; // maximum staleness in seconds
+        bool isActive;
+        uint8 custodianType; // 0=bank, 1=crypto, 2=fund_admin
+    }
+
+    struct ReserveAttestation {
+        uint256 balance;
+        uint256 timestamp;
+        bytes32 documentHash;
+        address attestor;
+        bool isValid;
+    }
+
+    /**
+     * @dev Get total reserve value across all active custodians
+     * @return totalValue Total reserve value in token denomination
+     * @return isValid Whether all required custodian data is current
+     */
+    function getTotalReserveValue() external view returns (uint256 totalValue, bool isValid);
+
+    /**
+     * @dev Get reserve value from specific custodian
+     * @param custodianId Unique identifier for custodian
+     * @return value Reserve value from this custodian
+     * @return isValid Whether this custodian's data is current
+     */
+    function getCustodianReserveValue(bytes32 custodianId) external view returns (uint256 value, bool isValid);
+
+    /**
+     * @dev Get custodian information
+     * @param custodianId Unique identifier for custodian
+     */
+    function getCustodianInfo(bytes32 custodianId) external view returns (CustodianInfo memory);
+
+    /**
+     * @dev Get latest attestation for a custodian
+     * @param custodianId Unique identifier for custodian
+     */
+    function getLatestAttestation(bytes32 custodianId) external view returns (ReserveAttestation memory);
+
+    /**
+     * @dev Check if reserve data is stale for any custodian
+     * @return isStale True if any custodian data exceeds heartbeat
+     * @return staleCustodians Array of custodian IDs with stale data
+     */
+    function checkDataStaleness() external view returns (bool isStale, bytes32[] memory staleCustodians);
+
+    // Events
+    event CustodianAdded(bytes32 indexed custodianId, string name, address oracle);
+    event CustodianUpdated(bytes32 indexed custodianId, address newOracle, uint256 newHeartbeat);
+    event CustodianDeactivated(bytes32 indexed custodianId);
+    event ReserveAttested(bytes32 indexed custodianId, uint256 balance, bytes32 documentHash);
+    event StaleDataDetected(bytes32 indexed custodianId, uint256 lastUpdate, uint256 heartbeat);
+}