Markdown links like `[xx](/workspaces)` written in `*.zh.mdx` rendered
as bare `<a href="/workspaces">`, which Next's basePath rewrote to
`/docs/workspaces` and the docs middleware then routed to English —
silently kicking Chinese readers out of their locale on every internal
click.
Add a `LocaleLink` MDX `a` override that runs every internal href
through `prefixLocale(href, lang)` before passing it to `next/link`, and
wire a `DocsLocaleProvider` around the MDX body in both page entry
points so the override and `NumberedCard` know the active locale.
External links, in-page anchors, relative paths, already-prefixed
paths, and default-language pages are deliberately left untouched.
Closes the bug reported in https://github.com/multica-ai/multica/issues/2173.
Co-authored-by: multica-agent <github@multica.ai>
