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/kefu/library/StrComparison.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace addons\kefu\library;
+
+class StrComparison
+{
+    protected $str1;
+    protected $str2;
+    protected $c = [];
+
+    /*
+     * 返回串一和串二的最长公共子序列
+     */
+    public function getLCS($str1, $str2, $len1 = 0, $len2 = 0)
+    {
+        $this->str1 = $str1;
+        $this->str2 = $str2;
+        if ($len1 == 0) {
+            $len1 = strlen($str1);
+        }
+        if ($len2 == 0) {
+            $len2 = strlen($str2);
+        }
+        $this->initC($len1, $len2);
+        return $this->printLCS($this->c, $len1 - 1, $len2 - 1);
+    }
+
+    /*
+     * 返回两个串的相似度
+     */
+    public function getSimilar($str1, $str2)
+    {
+        $len1    = strlen($str1);
+        $len2    = strlen($str2);
+        $len     = strlen($this->getLCS($str1, $str2, $len1, $len2));
+        $similar = $len * 2 / ($len1 + $len2);
+        return round($similar * 100, 2);
+    }
+
+    public function initC($len1, $len2)
+    {
+        for ($i = 0; $i < $len1; $i++) {
+            $this->c[$i][0] = 0;
+        }
+        for ($j = 0; $j < $len2; $j++) {
+            $this->c[0][$j] = 0;
+        }
+        for ($i = 1; $i < $len1; $i++) {
+            for ($j = 1; $j < $len2; $j++) {
+                if ($this->str1[$i] == $this->str2[$j]) {
+                    $this->c[$i][$j] = $this->c[$i - 1][$j - 1] + 1;
+                } elseif ($this->c[$i - 1][$j] >= $this->c[$i][$j - 1]) {
+                    $this->c[$i][$j] = $this->c[$i - 1][$j];
+                } else {
+                    $this->c[$i][$j] = $this->c[$i][$j - 1];
+                }
+            }
+        }
+    }
+
+    public function printLCS($c, $i, $j)
+    {
+        if ($i == 0 || $j == 0) {
+            if ($this->str1[$i] == $this->str2[$j]) {
+                return $this->str2[$j];
+            } else {
+                return "";
+            }
+        }
+        if ($this->str1[$i] == $this->str2[$j]) {
+            return $this->printLCS($this->c, $i - 1, $j - 1) . $this->str2[$j];
+        } elseif ($this->c[$i - 1][$j] >= $this->c[$i][$j - 1]) {
+            return $this->printLCS($this->c, $i - 1, $j);
+        } else {
+            return $this->printLCS($this->c, $i, $j - 1);
+        }
+    }
+}