internal/oauth: remove debug logs, and move them to the caller

Wrap errors in the OAuth manager instead of logging them, preserving
the underlying cause while allowing callers to detect startup failures.

Log failures at the fallback handler and scope the device-code login
result to its branch.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

internal/oauth/manager/manager.go

@@ -18,8 +18,6 @@ import (
 	"github.com/docker/cli/internal/registry"
 	"github.com/docker/cli/internal/tui"
 	"github.com/morikuni/aec"
-	"github.com/sirupsen/logrus"
-
 	"github.com/pkg/browser"
 )
 
@@ -89,13 +87,11 @@ func (m *OAuthManager) LoginDevice(ctx context.Context, w io.Writer) (*types.Aut
 
 	state, err := m.api.GetDeviceCode(ctx, m.audience)
 	if err != nil {
-		logrus.Debugf("failed to start device code login: %v", err)
-		return nil, ErrDeviceLoginStartFail
+		return nil, fmt.Errorf("%w: %w", ErrDeviceLoginStartFail, err)
 	}
 
 	if state.UserCode == "" {
-		logrus.Debugf("failed to start device code login: missing user code")
-		return nil, ErrDeviceLoginStartFail
+		return nil, fmt.Errorf("%w: missing user code", ErrDeviceLoginStartFail)
 	}
 
 	var out tui.Output