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

addons/translate/library/guzzlehttp/psr7/composer.json

@@ -0,0 +1,49 @@
+{
+    "name": "guzzlehttp/psr7",
+    "type": "library",
+    "description": "PSR-7 message implementation that also provides common utility methods",
+    "keywords": ["request", "response", "message", "stream", "http", "uri", "url", "psr-7"],
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Michael Dowling",
+            "email": "mtdowling@gmail.com",
+            "homepage": "https://github.com/mtdowling"
+        },
+        {
+            "name": "Tobias Schultze",
+            "homepage": "https://github.com/Tobion"
+        }
+    ],
+    "require": {
+        "php": ">=5.4.0",
+        "psr/http-message": "~1.0",
+        "ralouphie/getallheaders": "^2.0.5 || ^3.0.0"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "~4.8.36 || ^5.7.27 || ^6.5.8",
+        "ext-zlib": "*"
+    },
+    "provide": {
+        "psr/http-message-implementation": "1.0"
+    },
+    "suggest": {
+        "zendframework/zend-httphandlerrunner": "Emit PSR-7 responses"
+    },
+    "autoload": {
+        "psr-4": {
+            "GuzzleHttp\\Psr7\\": "src/"
+        },
+        "files": ["src/functions_include.php"]
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "GuzzleHttp\\Tests\\Psr7\\": "tests/"
+        }
+    },
+    "extra": {
+        "branch-alias": {
+            "dev-master": "1.6-dev"
+        }
+    }
+}