[Jotatavo]

Summary

Removes the Binance page (/binance) and every reference to it:

• docs/binance.md and its seven translations (es, fr, it, ja, ko, pt, zh).
• The Binance entry in the mkdocs.yml nav.
• The Binance section in hooks/emit_markdown.py, so it's no longer listed in llms.txt.
• The docs/binance.md entry in translations.json.

No other page links to it, so nothing else changes. The translate workflow has nothing to translate, since the only English change is a deletion.