🔧 refactor(auth, channel, context): improve context setup and validation for multi-key channels

relay/channel/vertex/relay-vertex.go

@@ -4,8 +4,11 @@ import "one-api/common"
 
 func GetModelRegion(other string, localModelName string) string {
 	// if other is json string
-	if common.IsJsonStr(other) {
-		m := common.StrToMap(other)
+	if common.IsJsonObject(other) {
+		m, err := common.StrToMap(other)
+		if err != nil {
+			return other // return original if parsing fails
+		}
 		if m[localModelName] != nil {
 			return m[localModelName].(string)
 		} else {