feat(http): add IssuerBase method for account site redirect

internal/auth/oauth.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"log"
 	"net/http"
+	"net/url"
 	"slices"
 	"time"
 
@@ -21,6 +22,17 @@ var (
 	authCookie string = "outfit-voting-abi26-auth"
 )
 
+func IssuerBaseURL() string {
+	urlstring := provider.Endpoint().AuthURL
+
+	url, err := url.Parse(urlstring)
+	if err != nil {
+		return ""
+	}
+	url.Path = "/"
+	return url.String()
+}
+
 func InitProvider(issuer, id, secret, redirect string) error {
 	ctx = context.Background()
 	var err error