feat: disable wechat payment channel, keep alipay only

- Remove wechat from provider options
- Set alipay as default payment channel
- Only alipay is currently enabled for unipay

wwwroot/recharge.ui

@@ -8,13 +8,9 @@
 			"name":"provider",
 			"uitype":"code",
 			"required":true,
-				"defautvalue":"wechat",
+			"defaultvalue":"alipay",
 			"label":"充值渠道",
 			"data":[
-					{
-						"value":"wechat",
-						"text":"微信支付"
-					},
 				{
 					"value":"alipay",
 					"text":"支付宝"