fix(test): address code review feedback for e2e tests

- error_test.go: fail test on wrong error type instead of just logging
- error_test.go: remove unused targetDir variable
- README.md: add prerequisites for Java 25 and goctl installation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: spencercjh <spencercjh@gmail.com>

Author: spencercjh

integration-tests/README.md

@@ -22,7 +22,13 @@ go test ./...
 
 ### End-to-End Tests
 
-E2E tests require the build tools (Maven/Gradle) to be installed.
+E2E tests require the following tools to be installed:
+
+- **Java 25** - Required for Spring Boot projects (Maven/Gradle wrappers are included in demo projects)
+- **goctl** - Required for go-zero projects. Install with:
+  ```bash
+  go install github.com/zeromicro/go-zero/tools/goctl@latest
+  ```
 
 ```bash
 # Run all e2e tests

integration-tests/error_test.go

@@ -21,12 +21,6 @@ func TestE2E_ErrorHandling_CommandNotFound(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// Create target directory with a dummy spec (simulating pre-existing spec)
-	targetDir := filepath.Join(tmpDir, "target")
-	if err := os.Mkdir(targetDir, 0o755); err != nil {
-		t.Fatal(err)
-	}
-
 	ctx := context.Background()
 	exec := executor.NewExecutor()
 
@@ -42,6 +36,6 @@ func TestE2E_ErrorHandling_CommandNotFound(t *testing.T) {
 
 	// Verify it's a CommandNotFoundError
 	if _, ok := errors.AsType[*executor.CommandNotFoundError](err); !ok {
-		t.Logf("Got error type %T: %v", err, err)
+		t.Fatalf("expected CommandNotFoundError, got %T: %v", err, err)
 	}
 }