fix(zh): translate ParamFields in site-level-settings (footer/bg/typography/layout/theme/settings)

Continue the LLM-translator-prompt pass through site-level-settings.mdx.
Translated ParamFields and inline notes for: footer-links (12 fields),
background-image (2), typography (3 + 5 font detail fields), layout
(12 fields including searchbar/tabs/switcher/content/header/etc),
theme (9 fields), and settings (10 fields including search, http
snippets, 404 handling, env-var substitution).

Code blocks, schema field names, prop names, brand identifiers, CSS
classes, and version strings stay verbatim.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Deep Singhvi