refactor: improve error bubbling implementation based on PR feedback

- Replace confusing variable names (_err2 -> _err, _ret -> _returnData) in ExecutionEnvironment.sol
- Update test naming convention to follow project standards (test_ErrorHandling_*)
- Replace try-catch pattern with low-level call pattern in tests for cleaner code
- Remove console.log statements from tests
- Add comprehensive test coverage for all error bubbling scenarios:
  - PreOps failures
  - UserOp delegatecall and regular call failures
  - AllocateValue failures
  - PreSolver and PostSolver failures
  - Security test for malicious solver error spoofing
- Fix test configuration to include proper gas limits for all UserOperations

These changes address all feedback from PR #500 while maintaining the core functionality
of preserving Atlas error selectors with appended DApp error data.

Co-Authored-By: BenSparksCode <noreply@github.com>

Author: Error Log Analyzer Bot

src/contracts/common/ExecutionEnvironment.sol

@@ -93,9 +93,9 @@ contract ExecutionEnvironment is Base {
             // regular user call - executed at regular destination and not performed locally
             (_success, returnData) = userOp.dapp.call{ value: userOp.value }(_data);
             if (!_success) {
-                bytes memory _err2 = abi.encodePacked(AtlasErrors.UserWrapperCallFail.selector, returnData);
+                bytes memory _err = abi.encodePacked(AtlasErrors.UserWrapperCallFail.selector, returnData);
                 assembly {
-                    revert(add(_err2, 32), mload(_err2))
+                    revert(add(_err, 32), mload(_err))
                 }
             }
         }
@@ -143,11 +143,11 @@ contract ExecutionEnvironment is Base {
             bool _success;
 
             bytes memory _data = _forward(abi.encodeCall(IDAppControl.preSolverCall, (solverOp, returnData)));
-            bytes memory _ret;
-            (_success, _ret) = _control().delegatecall(_data);
+            bytes memory _returnData;
+            (_success, _returnData) = _control().delegatecall(_data);
 
             if (!_success) {
-                bytes memory _err = abi.encodePacked(AtlasErrors.PreSolverFailed.selector, _ret);
+                bytes memory _err = abi.encodePacked(AtlasErrors.PreSolverFailed.selector, _returnData);
                 assembly {
                     revert(add(_err, 32), mload(_err))
                 }
@@ -194,11 +194,11 @@ contract ExecutionEnvironment is Base {
             bool _success;
 
             bytes memory _data = _forward(abi.encodeCall(IDAppControl.postSolverCall, (solverOp, returnData)));
-            bytes memory _ret;
-            (_success, _ret) = _control().delegatecall(_data);
+            bytes memory _returnData;
+            (_success, _returnData) = _control().delegatecall(_data);
 
             if (!_success) {
-                bytes memory _err = abi.encodePacked(AtlasErrors.PostSolverFailed.selector, _ret);
+                bytes memory _err = abi.encodePacked(AtlasErrors.PostSolverFailed.selector, _returnData);
                 assembly {
                     revert(add(_err, 32), mload(_err))
                 }
@@ -251,11 +251,11 @@ contract ExecutionEnvironment is Base {
         allocateData =
             _forward(abi.encodeCall(IDAppControl.allocateValueCall, (solved, bidToken, bidAmount, allocateData)));
 
-        (bool _success, bytes memory _ret2) = _control().delegatecall(allocateData);
+        (bool _success, bytes memory _returnData) = _control().delegatecall(allocateData);
         if (!_success) {
-            bytes memory _err2 = abi.encodePacked(AtlasErrors.AllocateValueDelegatecallFail.selector, _ret2);
+            bytes memory _err = abi.encodePacked(AtlasErrors.AllocateValueDelegatecallFail.selector, _returnData);
             assembly {
-                revert(add(_err2, 32), mload(_err2))
+                revert(add(_err, 32), mload(_err))
             }
         }