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>

media_platform/xhs/extractor.py

@@ -29,16 +29,16 @@ class XiaoHongShuExtractor:
         pass
 
     def extract_note_detail_from_html(self, note_id: str, html: str) -> Optional[Dict]:
-        """从html中提取笔记详情
+        """Extract note details from HTML
 
         Args:
-            html (str): html字符串
+            html (str): HTML string
 
         Returns:
-            Dict: 笔记详情字典
+            Dict: Note details dictionary
         """
         if "noteDetailMap" not in html:
-            # 这种情况要么是出了验证码了，要么是笔记不存在
+            # Either a CAPTCHA appeared or the note doesn't exist
             return None
 
         state = re.findall(r"window.__INITIAL_STATE__=({.*})</script>", html)[
@@ -50,13 +50,13 @@ class XiaoHongShuExtractor:
         return None
 
     def extract_creator_info_from_html(self, html: str) -> Optional[Dict]:
-        """从html中提取用户信息
+        """Extract user information from HTML
 
         Args:
-            html (str): html字符串
+            html (str): HTML string
 
         Returns:
-            Dict: 用户信息字典
+            Dict: User information dictionary
         """
         match = re.search(
             r"<script>window.__INITIAL_STATE__=(.+)<\/script>", html, re.M