fix(trading-service): 区块链充值 balanceBefore 从 trading_accounts 读取

修复 MarketMakerDepositConsumerService 读取 market_maker_configs.cash_balance
作为 balanceBefore 的 bug。该字段由中心化充值路径不维护，导致区块链充值
流水中 balanceBefore 始终为 0 或脱轨值。

改为与 deposit()/withdraw() 一致：
- balanceBefore 从 trading_accounts 读取（权威数据源）
- 删除对 market_maker_configs.cash_balance 的写操作

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/services/trading-service/src/infrastructure/kafka/market-maker-deposit-consumer.service.ts

@@ -204,25 +204,23 @@ export class MarketMakerDepositConsumerService implements OnModuleInit, OnModule
         }
 
         // 2. 根据资产类型更新余额
+        // 与中心化充值保持一致：只操作 trading_accounts，balanceBefore 从 trading_accounts 读取
         const assetField = payload.assetType === 'EUSDT' ? 'shareBalance' : 'cashBalance';
-        const currentBalance = payload.assetType === 'EUSDT'
-          ? marketMaker.shareBalance
-          : marketMaker.cashBalance;
-        const newBalance = currentBalance.add(new Prisma.Decimal(payload.amountFormatted));
+        const depositAmount = new Prisma.Decimal(payload.amountFormatted);
 
-        // 更新做市商配置余额
-        await tx.marketMakerConfig.update({
-          where: { id: marketMaker.id },
-          data: {
-            [assetField]: newBalance,
-          },
+        const tradingAccountBefore = await tx.tradingAccount.findUnique({
+          where: { accountSequence: marketMaker.accountSequence },
         });
+        const currentBalance = tradingAccountBefore
+          ? (payload.assetType === 'EUSDT' ? tradingAccountBefore.shareBalance : tradingAccountBefore.cashBalance)
+          : new Prisma.Decimal(0);
+        const newBalance = currentBalance.add(depositAmount);
 
-        // 同步更新交易账户余额（getConfig 从 trading_accounts 读取余额）
+        // 更新交易账户余额（权威数据源，与中心化充值路径一致）
         await tx.tradingAccount.update({
           where: { accountSequence: marketMaker.accountSequence },
           data: {
-            [assetField]: { increment: new Prisma.Decimal(payload.amountFormatted) },
+            [assetField]: { increment: depositAmount },
           },
         });
 
@@ -232,7 +230,7 @@ export class MarketMakerDepositConsumerService implements OnModuleInit, OnModule
             marketMakerId: marketMaker.id,
             type: 'DEPOSIT',
             assetType: payload.assetType === 'EUSDT' ? 'SHARE' : 'CASH',
-            amount: new Prisma.Decimal(payload.amountFormatted),
+            amount: depositAmount,
             balanceBefore: currentBalance,
             balanceAfter: newBalance,
             memo: `区块链充值: ${payload.txHash.slice(0, 10)}... (${payload.fromAddress.slice(0, 10)}...)`,