fix(trading): getConfig 自动从环境变量填充空的钱包地址

之前只有 initializeConfig 会读取 env 填充钱包地址，
getConfig 只读数据库。导致新增 eusdtWalletAddress 字段后
即使 .env 配置了地址，前端仍显示"未配置"。

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/services/trading-service/src/application/services/market-maker.service.ts

@@ -85,6 +85,25 @@ export class MarketMakerService {
     });
     if (!config) return null;
 
+    // 自动从环境变量填充空的钱包地址
+    const updateData: Record<string, string> = {};
+    if (!config.kavaWalletAddress) {
+      const addr = this.configService.get<string>('FUSDT_MARKET_MAKER_ADDRESS');
+      if (addr) updateData.kavaWalletAddress = addr;
+    }
+    if (!config.eusdtWalletAddress) {
+      const addr = this.configService.get<string>('EUSDT_MARKET_MAKER_ADDRESS');
+      if (addr) updateData.eusdtWalletAddress = addr;
+    }
+    if (Object.keys(updateData).length > 0) {
+      await this.prisma.marketMakerConfig.update({
+        where: { name },
+        data: updateData,
+      });
+      Object.assign(config, updateData);
+      this.logger.log(`Auto-filled wallet addresses from env for ${name}: ${JSON.stringify(updateData)}`);
+    }
+
     // 从交易账户获取实际余额（保证一致性）
     const tradingAccount = await this.accountRepository.findByAccountSequence(config.accountSequence);
     const cashBalance = tradingAccount ? new Decimal(tradingAccount.cashBalance.value.toString()) : new Decimal(0);