Batch 5: Content optimization and language tagging

- Add language tags to content files (lang: en/zh)
- Add frontmatter to Design Your Habits.md (English content)
- Add frontmatter to 自行车.md (Chinese content)
- Final verification: 28 markdown files in 200-area/

(vault changes by Claude Code)

200-area/Health/自行车.md

@@ -1,3 +1,10 @@
+---
+title: 自行车
+tags: [health, garmin, cycling, data-sync]
+lang: zh
+created: 2025-12-29
+updated: 2025-12-29
+---
 
 ###  数据同步
 

200-area/Personal Development/Design Your Habits.md

@@ -1,3 +1,11 @@
+---
+title: Design Your Habits
+tags: [personal-development, habits, productivity]
+lang: en
+created: 2025-12-29
+updated: 2025-12-29
+---
+
 Teacher: [[Tiago Forte]]
 
 ## Highlights: