chore(cfg): Change default database to SQLite

- Switch default DB type from mysql to sqlite
    - Update default DSN to local SQLite file path /tmp/vbase.db

cfg/cfg.go

@@ -51,9 +51,9 @@ type InitAdminConfig struct {
 // Global全局配置实例
 var Global = &Options{
 	DB: config.Database{
-		Type:   "mysql",
+		Type:   "sqlite",
 		Prefix: "vb_",
-		DSN:    "root:123456@tcp(127.0.0.1:3306)/vbase?charset=utf8mb4&parseTime=True&loc=Local",
+		DSN:    "/tmp/vbase.db",
 	},
 	Redis: config.Redis{
 		Addr: "memory",