fix: trim whitespace from register inputs (#1147)

Secrets often carry a trailing newline, for example from `echo "token" | base64`, which made `register --no-interactive` fail with `runner registration token not found`. The interactive path already trims typed values, this aligns the flag path.

Related to: https://gitea.com/gitea/runner/issues/727

Reviewed-on: https://gitea.com/gitea/runner/pulls/1147
Reviewed-by: techknowlogick <9+techknowlogick@noreply.gitea.com>
Co-authored-by: silverwind <me@silverwind.io>

internal/app/cmd/register.go

@@ -230,9 +230,9 @@ func initInputs(regArgs *registerArgs) (*registerInputs, error) {
 		token = envToken
 	}
 	inputs := &registerInputs{
-		InstanceAddr: regArgs.InstanceAddr,
-		Token:        token,
-		RunnerName:   regArgs.RunnerName,
+		InstanceAddr: strings.TrimSpace(regArgs.InstanceAddr),
+		Token:        strings.TrimSpace(token),
+		RunnerName:   strings.TrimSpace(regArgs.RunnerName),
 		Ephemeral:    regArgs.Ephemeral,
 	}
 	regArgs.Labels = strings.TrimSpace(regArgs.Labels)