fix: 修复交易统计和L2认证问题

- 修复交易统计数据计算逻辑（总订单数、已完成订单数、持仓数量）
- 修复L2认证签名生成，支持URL-safe base64格式的secret
- 添加标准HTTP请求头以匹配clob-client行为
- 移除数据库加密（私人应用，明文存储）
- 添加自动获取API Key功能
- 优化持仓数量统计（包括正负仓位）
- 添加EIP-712签名和L1认证支持
- 更新前端账户管理界面

polymarket-demo/src/createOrder.ts

@@ -0,0 +1,40 @@
+//npm install @polymarket/clob-client
+//npm install ethers
+//Client initialization example and dumping API Keys
+
+import { ApiKeyCreds, ClobClient, OrderType, Side, } from "@polymarket/clob-client";
+import { Wallet } from "@ethersproject/wallet";
+
+const host = 'https://clob.polymarket.com';
+const funder = ''; //This is the address listed below your profile picture when using the Polymarket site.
+const signer = new Wallet("[PRIVATE_KEY_REMOVED]"); //This is your Private Key. If using email login export from https://reveal.magic.link/polymarket otherwise export from your Web3 Application
+
+
+//In general don't create a new API key, always derive or createOrDerive
+const creds = new ClobClient(host, 137, signer).createOrDeriveApiKey();
+
+//1: Magic/Email Login
+//2: Browser Wallet(Metamask, Coinbase Wallet, etc)
+//0: EOA (If you don't know what this is you're not using it)
+
+const signatureType = 1; 
+  (async () => {
+    const clobClient = new ClobClient(host, 137, signer, await creds, signatureType, funder);
+    const resp2 = await clobClient.createAndPostOrder(
+        {
+            tokenID: "114304586861386186441621124384163963092522056897081085884483958561365015034812", //Use https://docs.polymarket.com/developers/gamma-markets-api/get-markets to grab a sample token
+            price: 0.01,
+            side: Side.BUY,
+            size: 5,
+            feeRateBps: 0,
+        },
+        { tickSize: "0.01",negRisk: false }, //You'll need to adjust these based on the market. Get the tickSize and negRisk T/F from the get-markets above
+        //Refer to the API documentation to locate a tokenID: https://docs.polymarket.com/developers/gamma-markets-api/fetch-markets-guide
+        //Example token: 114304586861386186441621124384163963092522056897081085884483958561365015034812 ( Xi Jinping out in 2025, YES side )
+        //{ tickSize: "0.001",negRisk: true },
+
+        OrderType.GTC, 
+    );
+    console.log(resp2)
+  })();
+