feat: 后端全量更新 - 含所有本次需求

- Contract.php: 返回合约账户余额(balance_contract)
- My.php: 地址管理增加BTC/ETH
- AppContract.php: 一键平仓(closeall)
- AppProxy.php: 代理专属注册链接 + 分级权限(L1/L2)
- site.php: 手续费减半(0.018→0.009)
- agent_permission_setup.sql: 代理权限SQL
- crypto_news_crawler.py: 新闻自动采集脚本

application/admin/view/app/app_exchange_set/add.html

@@ -0,0 +1,34 @@
+<form id="add-form" class="form-horizontal" role="form" data-toggle="validator" method="POST" action="">
+
+    <div class="form-group">
+        <label class="control-label col-xs-12 col-sm-2">{:__('Name')}:</label>
+        <div class="col-xs-12 col-sm-8">
+            <input id="c-name" data-rule="required" class="form-control" name="row[name]" type="text" value="">
+        </div>
+    </div>
+    <div class="form-group">
+        <label class="control-label col-xs-12 col-sm-2">{:__('Name_sx')}:</label>
+        <div class="col-xs-12 col-sm-8">
+            <input id="c-name_sx" class="form-control" name="row[name_sx]" type="text" value="">
+        </div>
+    </div>
+    <div class="form-group">
+        <label class="control-label col-xs-12 col-sm-2">{:__('Exchange')}:</label>
+        <div class="col-xs-12 col-sm-8">
+            <input id="c-exchange" data-rule="required" class="form-control" step="0.0001" name="row[exchange]" type="number" value="0.0000">
+        </div>
+    </div>
+    <div class="form-group">
+        <label class="control-label col-xs-12 col-sm-2">{:__('Sign')}:</label>
+        <div class="col-xs-12 col-sm-8">
+            <input id="c-sign" data-rule="required" class="form-control" name="row[sign]" type="text" value="">
+        </div>
+    </div>
+    <div class="form-group layer-footer">
+        <label class="control-label col-xs-12 col-sm-2"></label>
+        <div class="col-xs-12 col-sm-8">
+            <button type="submit" class="btn btn-success btn-embossed disabled">{:__('OK')}</button>
+            <button type="reset" class="btn btn-default btn-embossed">{:__('Reset')}</button>
+        </div>
+    </div>
+</form>