Consolidate webapp structure by merging nested components into the main repository

contracts/interfaces/IAdapter.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+/**
+ * @title IAdapter
+ * @notice Interface for protocol adapters
+ */
+interface IAdapter {
+    /**
+     * @notice Execute a step using this adapter
+     * @param data Encoded step parameters
+     * @return success Whether execution succeeded
+     * @return returnData Return data from execution
+     */
+    function executeStep(bytes calldata data) external returns (bool success, bytes memory returnData);
+
+    /**
+     * @notice Prepare step (2PC prepare phase)
+     * @param data Encoded step parameters
+     * @return prepared Whether preparation succeeded
+     */
+    function prepareStep(bytes calldata data) external returns (bool prepared);
+
+    /**
+     * @notice Get adapter name
+     */
+    function name() external view returns (string memory);
+
+    /**
+     * @notice Get adapter type (DEFI or FIAT_DTL)
+     */
+    function adapterType() external view returns (uint8);
+}
+