feat(datasource): 实现加密货币数据获取功能

- 新增 ccxt_source.py: CCXT + OKX 加密货币数据源
- 新增 socks2http.py: SOCKS5 转 HTTP 代理转换器
- 修改 universal_fetcher.py: 添加 _fetch_crypto 方法，支持 timeframe 参数
- 修改 flask_server.py: API 支持 timeframe 参数，加密货币不缓存

支持的 timeframe: 1d, 1h, 4h, 15m, 1m
测试验证: BTC 数据获取成功

datasource/socks2http.py

@@ -0,0 +1,168 @@
+#!/usr/bin/env python3
+"""
+SOCKS5 转 HTTP 代理转发工具
+将 SSH 隧道的 SOCKS5 代理 (1080) 转为 HTTP 代理 (8080)
+供 CCXT 等只支持 HTTP 代理的库使用
+"""
+
+import socket
+import threading
+import select
+import sys
+from urllib.parse import urlparse
+
+
+class Socks2Http:
+    def __init__(self, socks_host='127.0.0.1', socks_port=1080, http_port=8080):
+        self.socks_host = socks_host
+        self.socks_port = socks_port
+        self.http_port = http_port
+        self.server = None
+        self.running = False
+        
+    def start(self):
+        """启动 HTTP 代理服务器"""
+        self.server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        self.server.bind(('127.0.0.1', self.http_port))
+        self.server.listen(5)
+        self.running = True
+        
+        print(f"HTTP 代理已启动: http://127.0.0.1:{self.http_port}")
+        print(f"转发到 SOCKS5: {self.socks_host}:{self.socks_port}")
+        
+        while self.running:
+            try:
+                client, addr = self.server.accept()
+                thread = threading.Thread(target=self._handle_client, args=(client,))
+                thread.daemon = True
+                thread.start()
+            except Exception as e:
+                if self.running:
+                    print(f"接受连接错误: {e}")
+                    
+    def stop(self):
+        """停止代理服务器"""
+        self.running = False
+        if self.server:
+            self.server.close()
+        print("HTTP 代理已停止")
+        
+    def _handle_client(self, client):
+        """处理客户端连接"""
+        try:
+            # 读取 HTTP 请求
+            request = client.recv(4096)
+            if not request:
+                client.close()
+                return
+                
+            # 解析 CONNECT 请求
+            first_line = request.split(b'\r\n')[0].decode('utf-8', errors='ignore')
+            
+            if first_line.startswith('CONNECT'):
+                # HTTPS 代理
+                parts = first_line.split()
+                if len(parts) >= 2:
+                    target = parts[1]
+                    host, port = target.rsplit(':', 1)
+                    port = int(port)
+                    
+                    # 连接到 SOCKS5 代理
+                    remote = self._connect_via_socks5(host, port)
+                    if remote:
+                        client.send(b'HTTP/1.1 200 Connection established\r\n\r\n')
+                        self._relay(client, remote)
+                    else:
+                        client.send(b'HTTP/1.1 502 Bad Gateway\r\n\r\n')
+            else:
+                # HTTP 代理
+                lines = first_line.split()
+                if len(lines) >= 2:
+                    url = lines[1]
+                    parsed = urlparse(url)
+                    host = parsed.hostname
+                    port = parsed.port or 80
+                    
+                    # 连接到 SOCKS5 代理
+                    remote = self._connect_via_socks5(host, port)
+                    if remote:
+                        # 修改请求，去掉完整 URL
+                        new_request = request.replace(
+                            f'{lines[0]} {url} '.encode(),
+                            f'{lines[0]} {parsed.path or "/"}{"?" + parsed.query if parsed.query else ""} '.encode()
+                        )
+                        remote.send(new_request)
+                        self._relay(client, remote)
+                        
+        except Exception as e:
+            print(f"处理客户端错误: {e}")
+        finally:
+            client.close()
+            
+    def _connect_via_socks5(self, host, port):
+        """通过 SOCKS5 代理连接目标服务器"""
+        try:
+            # 连接到 SOCKS5 代理
+            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            sock.settimeout(30)
+            sock.connect((self.socks_host, self.socks_port))
+            
+            # SOCKS5 握手
+            # 1. 发送认证方法
+            sock.send(b'\x05\x01\x00')  # VER=5, NMETHODS=1, METHOD=0 (无认证)
+            resp = sock.recv(2)
+            if resp[0] != 0x05 or resp[1] != 0x00:
+                sock.close()
+                return None
+                
+            # 2. 发送连接请求
+            req = b'\x05\x01\x00\x03'  # VER=5, CMD=CONNECT, RSV=0, ATYP=DOMAIN
+            req += bytes([len(host)]) + host.encode()
+            req += bytes([(port >> 8) & 0xFF, port & 0xFF])
+            sock.send(req)
+            
+            # 3. 读取响应
+            resp = sock.recv(10)
+            if len(resp) < 4 or resp[1] != 0x00:
+                sock.close()
+                return None
+                
+            return sock
+            
+        except Exception as e:
+            print(f"SOCKS5 连接错误: {e}")
+            return None
+            
+    def _relay(self, client, remote):
+        """双向转发数据"""
+        try:
+            while True:
+                readable, _, _ = select.select([client, remote], [], [], 60)
+                if not readable:
+                    break
+                    
+                if client in readable:
+                    data = client.recv(4096)
+                    if not data:
+                        break
+                    remote.send(data)
+                    
+                if remote in readable:
+                    data = remote.recv(4096)
+                    if not data:
+                        break
+                    client.send(data)
+        except:
+            pass
+        finally:
+            client.close()
+            remote.close()
+
+
+if __name__ == '__main__':
+    proxy = Socks2Http(socks_port=1080, http_port=8080)
+    try:
+        proxy.start()
+    except KeyboardInterrupt:
+        proxy.stop()