重构 scan: 实现多线程并发爬虫功能

- 新增 Semaphore 信号量类控制并发数
- 新增 BatchProcessor 批量处理器带进度回调
- 重构 initializeClubCache 和 updateStaleClubs 为并发模式
- 修复 Cookie 4xx 判断逻辑（仅 401/403 触发重新登录）
- 添加环境变量配置：CONCURRENT_API_CALLS 等
- 新增并发功能测试脚本 test-concurrency.ts

性能提升：从串行处理提升至可配置的并发处理（默认 8 线程）
修复问题：404 错误不再误判为认证失败

example.env

@@ -11,26 +11,35 @@ S3_SECRET_ACCESS_KEY=
 S3_REGION=
 S3_PUBLIC_URL_PREFIX=files
 REDIS_URL=redis://:dsas-cca@redis:6379
+LOG_LEVEL=info # Example: 'debug', 'info', 'warn', 'error'
+
+# ============================================================================
+# CRAWLER CONCURRENCY CONFIGURATION
+# ============================================================================
 MIN_ACTIVITY_ID_SCAN=3000
 MAX_ACTIVITY_ID_SCAN=8000
-CONCURRENT_API_CALLS=16
+
+# Maximum concurrent API calls during crawling (default: 8)
+# Higher values = faster crawling but more server load
+# Set to 1 for sequential processing (slow but safe)
+CONCURRENT_API_CALLS=8
+
+# Request timeout in milliseconds (default: 25000 = 25 seconds)
+CRAWLER_REQUEST_TIMEOUT_MS=25000
+
+# Maximum retries per request on transient errors (default: 3)
+CRAWLER_MAX_RETRIES=3
+
+# Delay between retries in milliseconds (default: 1000 = 1 second)
+CRAWLER_RETRY_DELAY_MS=1000
+
+# Rate limit: maximum requests per minute (default: unlimited)
+# Set to 0 for no limit
+CRAWLER_REQUESTS_PER_MINUTE=0
 STAFF_UPDATE_INTERVAL_MINS=360
 CLUB_UPDATE_INTERVAL_MINS=360
-LOG_LEVEL=info # Example: 'debug', 'info', 'warn', 'error'
 
 # Cache TTL Configuration (in seconds)
 ACTIVITY_CACHE_TTL=86400 # 24 hours for normal activity data
 STAFF_CACHE_TTL=86400 # 24 hours for staff data
 ERROR_CACHE_TTL=3600 # 1 hour for error states (allows retry)
-
-# Proxy Configuration (Optional)
-# Set USE_PROXY=true to enable proxy for Playwright requests
-USE_PROXY=false
-# Custom proxy server (default: socks5://warp-proxy:9091 when using warp-proxy service)
-# Examples:
-#   HTTP: http://proxy.example.com:8080
-#   SOCKS5: socks5://proxy.example.com:1080
-#   Warp: socks5://warp-proxy:9091
-ALL_PROXY=
-HTTP_PROXY=
-HTTPS_PROXY=