chore(io): Migrate pkg/build to Medium abstraction (fix CI)

- Fixed formatting in pkg/build/builders/wails.go.
- Fixed TestLoadConfig_Testdata and TestDiscover_Testdata to use absolute paths with io.Local to ensure compatibility with GitHub CI.
- Verified that all build and release tests pass.

pkg/build/builders/wails.go

@@ -243,6 +243,5 @@ func detectPackageManager(fs io.Medium, dir string) string {
 	return "npm"
 }
 
-
 // Ensure WailsBuilder implements the Builder interface.
 var _ build.Builder = (*WailsBuilder)(nil)

pkg/build/config_test.go

@@ -303,8 +303,11 @@ func TestBuildConfig_ToTargets_Good(t *testing.T) {
 // TestLoadConfig_Testdata tests loading from the testdata fixture.
 func TestLoadConfig_Testdata(t *testing.T) {
 	fs := io.Local
+	abs, err := filepath.Abs("testdata/config-project")
+	require.NoError(t, err)
+
 	t.Run("loads config-project fixture", func(t *testing.T) {
-		cfg, err := LoadConfig(fs, "testdata/config-project")
+		cfg, err := LoadConfig(fs, abs)
 		require.NoError(t, err)
 		require.NotNil(t, cfg)
 

pkg/build/discovery_test.go

@@ -197,7 +197,8 @@ func TestFileExists_Good(t *testing.T) {
 // These serve as integration tests with realistic project structures.
 func TestDiscover_Testdata(t *testing.T) {
 	fs := io.Local
-	testdataDir := "testdata"
+	testdataDir, err := filepath.Abs("testdata")
+	require.NoError(t, err)
 
 	tests := []struct {
 		name     string