feat: add getter and tests

contracts/src/ProtocolAdapter.sol

@@ -186,6 +186,11 @@ contract ProtocolAdapter is
         isStopped = paused() || risc0Paused;
     }
 
+    /// @inheritdoc IProtocolAdapter
+    function getRiscZeroVerifierRouter() public view override returns (address verifierRouter) {
+        verifierRouter = address(_TRUSTED_RISC_ZERO_VERIFIER_ROUTER);
+    }
+
     /// @inheritdoc IProtocolAdapter
     function getRiscZeroVerifierSelector() public view override returns (bytes4 verifierSelector) {
         verifierSelector = _RISC_ZERO_VERIFIER_SELECTOR;

contracts/src/interfaces/IProtocolAdapter.sol

@@ -66,6 +66,10 @@ interface IProtocolAdapter {
     /// @return version The semantic version number.
     function getProtocolAdapterVersion() external view returns (bytes32 version);
 
+    /// @notice Returns the RISC Zero verifier router associated with the protocol adapter.
+    /// @return verifierRouter The RISC Zero verifier router.
+    function getRiscZeroVerifierRouter() external view returns (address verifierRouter);
+
     /// @notice Returns the RISC Zero verifier selector associated with the protocol adapter.
     /// @return verifierSelector The RISC Zero verifier selector.
     function getRiscZeroVerifierSelector() external view returns (bytes4 verifierSelector);

contracts/test/ProtocolAdapter.t.sol

@@ -121,6 +121,14 @@ contract ProtocolAdapterTest is Test {
         _pa.emergencyStop();
     }
 
+    function test_getRiscZeroVerifierRouter_returns_the_router_address() public view {
+        assertEq(_pa.getRiscZeroVerifierRouter(), address(_router));
+    }
+
+    function test_getRiscZeroVerifierSelector_returns_the_selector() public view {
+        assertEq(_pa.getRiscZeroVerifierSelector(), _verifierSelector);
+    }
+
     function test_getProtocolAdapterVersion_returns_a_semantic_version() public view {
         bytes32 version = _pa.getProtocolAdapterVersion();