i18n: translate all Chinese comments, docstrings, and logger messages to English

Comprehensive translation of Chinese text to English across the entire codebase:

- api/: FastAPI server documentation and logger messages
- cache/: Cache abstraction layer comments and docstrings
- database/: Database models and MongoDB store documentation
- media_platform/: All platform crawlers (Bilibili, Douyin, Kuaishou, Tieba, Weibo, Xiaohongshu, Zhihu)
- model/: Data model documentation
- proxy/: Proxy pool and provider documentation
- store/: Data storage layer comments
- tools/: Utility functions and browser automation
- test/: Test file documentation

Preserved: Chinese disclaimer header (lines 10-18) for legal compliance

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

base/base_crawler.py

@@ -53,14 +53,14 @@ class AbstractCrawler(ABC):
 
     async def launch_browser_with_cdp(self, playwright: Playwright, playwright_proxy: Optional[Dict], user_agent: Optional[str], headless: bool = True) -> BrowserContext:
         """
-        使用CDP模式启动浏览器（可选实现）
-        :param playwright: playwright实例
-        :param playwright_proxy: playwright代理配置
-        :param user_agent: 用户代理
-        :param headless: 无头模式
-        :return: 浏览器上下文
+        Launch browser using CDP mode (optional implementation)
+        :param playwright: playwright instance
+        :param playwright_proxy: playwright proxy configuration
+        :param user_agent: user agent
+        :param headless: headless mode
+        :return: browser context
         """
-        # 默认实现：回退到标准模式
+        # Default implementation: fallback to standard mode
         return await self.launch_browser(playwright.chromium, playwright_proxy, user_agent, headless)