Propose Russian, Ukrainian and German translation tracks

[OnePathToFreedom]

Summary

I'd like to propose adding Russian (ru), Ukrainian (uk), and German (de)
translations alongside the existing English/Chinese/Japanese tracks.

What's already done (as a sample)

On my fork, I've translated:

• root README.md → README-ru.md, README-uk.md, README-de.md
• s01_agent_loop/README.md → README.ru.md, README.uk.md, README.de.md

Both follow the existing conventions:

• language switcher line updated in all existing README files
• code blocks left byte-for-byte identical to the English source (verified by hash)
• technical terms (harness, agent loop, tool_use, subagent, hooks, skill,
  MCP, etc.) kept in English, with a short glossary note at the top of each
  translated file explaining them once instead of inline on every use
• mermaid/ASCII diagram labels translated, diagram syntax untouched

Fork: https://github.com/OnePathToFreedom/learn-claude-code

Disclosure

This translation work was produced with AI assistance and reviewed by me
for accuracy and terminology consistency before proposing it here.

Proposed scope / next steps

If this is welcome, I'd continue chapter by chapter (s02–s17), including:

• README.{ru,uk,de}.md for each chapter
• the SVG diagrams under each chapter's images/ folder, translated the
  same way the existing agent-loop.en.svg / agent-loop.ja.svg are
  localized versions of the source diagram
• docs/ru, docs/uk, docs/de for the web-facing docs
• web/src/i18n/messages/{ru,uk,de}.json locale files for the web app UI

Happy to split this into one PR per chapter, or one PR per language track —
whatever is easier to review. Let me know if this is something you'd want,
and in what shape.