fix: resolve multilingual issues — language switcher, missing READMEs, badge links

- Remove duplicate `root` locale from VitePress config (was conflicting with `en`, causing language switcher to show only 6/12 languages)
- Create missing README-RU.md and README-UZ.md at root level
- Create docs-readme/ru-RU/README.md and docs-readme/uz-UZ/README.md
- Fix all README badge links for RU/UZ from live-site URLs to local file paths (19 files)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -6,11 +6,11 @@
   <a href="docs-readme/ko-KR/README.md"><img alt="한국어" src="https://img.shields.io/badge/KO-한국어-blueviolet?style=flat-square"></a>
   <a href="docs-readme/es-ES/README.md"><img alt="Español" src="https://img.shields.io/badge/ES-Español-yellow?style=flat-square"></a>
   <a href="docs-readme/fr-FR/README.md"><img alt="Français" src="https://img.shields.io/badge/FR-Français-007EC6?style=flat-square"></a>
-  <a href="https://walkinglabs.github.io/learn-harness-engineering/ru/"><img alt="Русский" src="https://img.shields.io/badge/RU-Русский-informational?style=flat-square"></a>
+  <a href="docs-readme/ru-RU/README.md"><img alt="Русский" src="https://img.shields.io/badge/RU-Русский-informational?style=flat-square"></a>
   <a href="docs-readme/de-DE/README.md"><img alt="Deutsch" src="https://img.shields.io/badge/DE-Deutsch-2EA043?style=flat-square"></a>
   <a href="docs-readme/ar-SA/README.md"><img alt="العربية" src="https://img.shields.io/badge/AR-العربية-success?style=flat-square"></a>
   <a href="docs-readme/vi-VN/README.md"><img alt="Tiếng Việt" src="https://img.shields.io/badge/VI-Tiếng_Việt-cc6699?style=flat-square"></a>
-  <a href="https://walkinglabs.github.io/learn-harness-engineering/uz/"><img alt="Oʻzbekcha" src="https://img.shields.io/badge/UZ-Oʻzbekcha-1A8BBA?style=flat-square"></a>
+  <a href="docs-readme/uz-UZ/README.md"><img alt="Oʻzbekcha" src="https://img.shields.io/badge/UZ-Oʻzbekcha-1A8BBA?style=flat-square"></a>
 </p>
 
 <h1 align="center">Learn Harness Engineering</h1>