Changes:
- Move Quick Start before Five Steps (user sees 'how to use' in 30 seconds)
- Merge duplicate model routing sections into one
- Remove 15 Tools table (internal detail, users interact via skills)
- Remove Token Cost and Code Scale sections (not actionable for users)
- Collapse 10-rules customization guide into 2-line summary
- Collapse older changelogs into <details> fold
- Keep Design Philosophy & Acknowledgements unchanged
- Sync both EN and CN