Refactor and translate comments and docstrings in utility modules to English for better clarity and maintainability. Update Gunicorn and application startup messages for consistency in language. Enhance documentation with English translations for better accessibility.

backend_api_python/app/data_sources/__init__.py

@@ -1,11 +1,11 @@
 """
-数据源模块
-支持多种市场的K线数据获取
+data source module
+Support K-line data acquisition for multiple markets
 
-改进版本（参考 daily_stock_analysis 项目）:
-- 熔断器保护 (circuit_breaker)
-- 数据缓存 (cache_manager)
-- 防封禁策略 (rate_limiter)
+Improved version (refer to daily_stock_analysis project):
+- Fuse protection (circuit_breaker)
+- Data cache (cache_manager)
+- Anti-ban strategy (rate_limiter)
 """
 from app.data_sources.factory import DataSourceFactory
 from app.data_sources.circuit_breaker import (
@@ -26,17 +26,17 @@ from app.data_sources.rate_limiter import (
 )
 
 __all__ = [
-    # 工厂
+    # factory
     'DataSourceFactory',
-    # 熔断器
+    # fuse
     'CircuitBreaker',
     'get_realtime_circuit_breaker',
-    # 缓存
+    # cache
     'DataCache',
     'get_realtime_cache',
     'get_kline_cache',
     'get_stock_info_cache',
-    # 限流器
+    # current limiter
     'RateLimiter',
     'get_random_user_agent',
     'random_sleep',