feat: add worldid verification

src/Nebula.sol

@@ -1,4 +1,38 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.24;
 
-contract Nebula {}
+import {WorldIDVerifier} from "./WorldIDVerifier.sol";
+
+contract Nebula {
+    /// @dev Universal Nebula world id verifier
+    WorldIDVerifier verifier;
+
+    struct WorldIDProof {
+        address signal;
+        uint256 root;
+        uint256 nullifierHash;
+        uint256[8] proof;
+    }
+
+    /// @param _verifier Universal verifier for worldid
+    constructor(address _verifier) {
+        verifier = WorldIDVerifier(_verifier);
+    }
+
+    /// @notice Verifies a given proof
+    /// @param proof WorldID Proof
+    /// @param identity WorldID Proof
+    function verifyIdentity(
+        WorldIDProof calldata proof,
+        bytes8 identity
+    ) external {
+        verifier.verifyAndExecute(
+            proof.signal,
+            proof.root,
+            proof.nullifierHash,
+            proof.proof
+        );
+
+        // Resolve Identity, Verify and Issue
+    }
+}

src/WorldcoinVerifier.sol → src/WorldIDVerifier.sol

@@ -27,7 +27,7 @@ interface IWorldID {
     ) external view;
 }
 
-contract WorldcoinVerifier {
+contract WorldIDVerifier {
     using ByteHasher for bytes;
 
     /// @notice Thrown when attempting to reuse a nullifier
@@ -75,7 +75,7 @@ contract WorldcoinVerifier {
 
         worldId.verifyProof(
             root,
-            groupId, // set to "1" in the constructor
+            groupId,
             abi.encodePacked(signal).hashToField(),
             nullifierHash,
             externalNullifierHash,