Remove upgradeable app and fix #146

src/user/AppBase.sol

@@ -21,14 +21,7 @@ import "../interfaces/IORMP.sol";
 
 // https://eips.ethereum.org/EIPS/eip-5164
 abstract contract AppBase {
-    function protocol() public view virtual returns (address);
-
-    function _setAppConfig(address oracle, address relayer) internal virtual {
-        IORMP(protocol()).setAppConfig(oracle, relayer);
-    }
-
-    modifier onlyORMP() {
-        require(protocol() == msg.sender, "!ormp-recver");
+    modifier onlyORMP() virtual {
         _;
     }
 

src/user/Application.sol

@@ -20,13 +20,18 @@ pragma solidity ^0.8.17;
 import "./AppBase.sol";
 
 abstract contract Application is AppBase {
-    address private immutable _ORMP;
+    address public immutable ORMP;
+
+    modifier onlyORMP() override {
+        require(ORMP == msg.sender, "!ormp");
+        _;
+    }
 
     constructor(address ormp) {
-        _ORMP = ormp;
+        ORMP = ormp;
     }
 
-    function protocol() public view virtual override returns (address) {
-        return _ORMP;
+    function _setAppConfig(address oracle, address relayer) internal virtual {
+        IORMP(ORMP).setAppConfig(oracle, relayer);
     }
 }