增加pgx驱动，完善前端的代码，暂定supabase后端数据库

database/model.go

@@ -1,7 +1,10 @@
 package db
 
 import (
+	"github.com/jackc/pgx/v5/pgxpool"
 	"gorm.io/gorm"
 )
 
 var Main *gorm.DB //Main database connection
+
+var PGX *pgxpool.Pool