refactor(data/exchanges): 多子类架构 + 工厂入口

- 每个交易所独立子类：BinanceRestClient extends BaseRestClient
- 统一入口 createRestClient(exchangeId) 工厂函数
- KLINE_INTERVAL_MS 移至 constants.ts
- fetchKlines 签名统一为 (symbol, startTime, limit?, endTime?)
- throttle 限流实际生效
- convertBinanceKline interval 参数化
- 删除 filterConsecutive 死代码
- 更新 run/exchange.ts 和 service/bnkline.ts 调用方

data/run/exchange.ts

@@ -1,7 +1,7 @@
 import { logger } from "../utils/logger";
 import { getAllPairs, updatePairLastBackfillTime } from '../service/pair';
 import { upsertOrUpdateKlines } from "../service/kline";
-import { Client } from '../exchanges/rest';
+import { createRestClient } from '../exchanges';
 
 function getNowMinuteMS() {
     const minuteMS = 1000 * 60;
@@ -11,7 +11,7 @@ function getNowMinuteMS() {
 const allPairs = await getAllPairs();
 
 for (const pair of allPairs) {
-    const client = new Client("binance");
+    const client = createRestClient("binance");
     let lastBackfillTime = pair.last_backfill_time.getTime();
     try {
         while (lastBackfillTime < getNowMinuteMS()) {