fix(flaky test): use proto.Equal for gRPC status comparison in TestUpdateFeature (#2774)

* fix: use proto.Equal for gRPC status comparison in TestUpdateFeature

The status error comparison used assert.Equal on serialized proto bytes,
which is non-deterministic when ErrorInfo.Metadata has multiple map
entries (messageKey + field). Switch to proto.Equal for semantic
comparison.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: unpack Any details before proto.Equal comparison

proto.Equal on Status.Proto() compares Any.value raw bytes, which still
suffers from non-deterministic map serialization in ErrorInfo.Metadata.
Instead, compare code/message individually and use Details() to unpack
each Any into its concrete proto.Message before comparing with
proto.Equal.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: t-kikuc

pkg/feature/api/feature_test.go

@@ -26,6 +26,7 @@ import (
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/wrapperspb"
 
 	"github.com/bucketeer-io/bucketeer/v2/pkg/api/api"
@@ -3206,7 +3207,22 @@ func TestUpdateFeature(t *testing.T) {
 				p.setup(service)
 			}
 			_, err := service.UpdateFeature(p.ctx, p.input)
-			assert.Equal(t, p.expectedErr, err)
+			if p.expectedErr == nil {
+				assert.NoError(t, err)
+			} else {
+				require.Error(t, err)
+				expectedSt, _ := status.FromError(p.expectedErr)
+				actualSt, _ := status.FromError(err)
+				assert.Equal(t, expectedSt.Code(), actualSt.Code())
+				assert.Equal(t, expectedSt.Message(), actualSt.Message())
+				expectedDetails := expectedSt.Details()
+				actualDetails := actualSt.Details()
+				require.Equal(t, len(expectedDetails), len(actualDetails))
+				for i := range expectedDetails {
+					assert.True(t, proto.Equal(expectedDetails[i].(proto.Message), actualDetails[i].(proto.Message)),
+						"detail[%d]: expected %v, got %v", i, expectedDetails[i], actualDetails[i])
+				}
+			}
 		})
 	}
 }