feat: 增强爬虫系统功能和性能管理

- 新增爬虫状态接口：GET /api/crawler/status 可实时查看爬虫运行状态
- 防止重复爬取：添加 isCrawling 标志位，避免同时运行多个爬虫任务
- 增强爬虫服务：集成所有9个爬虫平台到 BidCrawlerService
- 添加执行时间限制：设置最大执行时间为1小时，防止任务无限运行
- 新增来源统计功能：GET /api/bids/sources 可查看所有招标来源平台
- 优化错误处理：完善爬虫完成后的时间统计和超时警告
- 改进控制器逻辑：更好的异常处理和状态管理
- 支持的平台包括：华能、大唐、华润、三峡、中核、中广核、电能e招采、大连能源、北京电力等9大采购平台

src/crawler/crawler.controller.ts

@@ -1,21 +1,38 @@
-import { Controller, Post } from '@nestjs/common';
+import { Controller, Post, Get } from '@nestjs/common';
 import { BidCrawlerService } from './services/bid-crawler.service';
 
 @Controller('api/crawler')
 export class CrawlerController {
+  private isCrawling = false;
+
   constructor(private readonly crawlerService: BidCrawlerService) {}
 
+  @Get('status')
+  getStatus() {
+    return { isCrawling: this.isCrawling };
+  }
+
   @Post('run')
   async runCrawl() {
+    if (this.isCrawling) {
+      return { message: 'Crawl is already running' };
+    }
+    
+    this.isCrawling = true;
+    
     // We don't await this because we want it to run in the background 
-    // and return immediately, or we can await if we want the user to wait.
+    // and return immediately, or we can await if we want to user to wait.
     // Given the requirement "Immediate Crawl", usually implies triggering it.
     // However, for a better UI experience, we might want to wait or just trigger.
-    // Let's await it so the user knows when it's done (or failed), 
+    // Let's await it so that user knows when it's done (or failed), 
     // assuming it doesn't take too long for the mock. 
     // Real crawling might take long, so background is better.
     // For this prototype, I'll await it to show completion.
-    await this.crawlerService.crawlAll();
-    return { message: 'Crawl completed successfully' };
+    try {
+      await this.crawlerService.crawlAll();
+      return { message: 'Crawl completed successfully' };
+    } finally {
+      this.isCrawling = false;
+    }
   }
 }