Add Russian localization and clean up README/Use Cases links and wording

[arty-kk]

Motivation

• Provide a Russian-language copy of the main docs and use-case commands so Russian-speaking users can consume the workflow skills.
• Improve README and Use Cases readability and correctness by fixing link markup and clarifying English phrasing where content was mixed.

Description

• Add README.ru.md and Use Cases.ru.md containing Russian translations and a link back to the English versions.
• Update README.md to add a top-level Russian link, convert file references with spaces to proper markdown links (e.g. Use Cases.md, CONTRIBUTING.md, LICENSE), and adjust a few lines of phrasing.
• Revise Use Cases.md to prepend a Russian-link reference, convert mixed Russian lines to clearer English phrasing while preserving Russian command examples, and ensure link/filename encoding for files with spaces.

Testing

• Ran the repository validator with bash scripts/validate.sh and the validation completed successfully.

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Codex Task