Translate 'assistant' contextual menu option to es/fr/zh

[mintlify]

Summary

• Translates the new assistant contextual menu option documentation to Spanish, French, and Chinese
• Mirrors changes from Add missing 'assistant' option to contextual menu docs #4343 which added the missing assistant option to the contextual menu documentation

---

Note

Low Risk
Low risk documentation-only change updating localized MDX content with no runtime impact.

Overview
Adds the missing "assistant" option to the documented contextual.options enum in es/organize/settings.mdx, fr/organize/settings.mdx, and zh/organize/settings.mdx, including a localized description of the action.

Also normalizes the options field’s type string in these locales to include "assistant" alongside the existing menu actions.

^{Written by Cursor Bugbot for commit 59d5520. This will update automatically on new commits. Configure here.}