Add German and Turkish documentation

[AGulev]

Adds German and Turkish versions of the manuals, tutorials, and FAQ, and enables both languages on the documentation site.

Technical changes

• Add 204 translated Markdown files per language: 160 manuals, 19 tutorials, 24 shared snippets, and 1 FAQ.
• Add terminology glossaries and translation guidelines for both languages.
• Register de and tr as active languages in docs/languages.json.
• Preserve code examples, API identifiers, include directives, and link destinations, with English anchors retained for existing fragment links.
• Validation: coverage, Markdown structure, frontmatter, and local-link checks passed for all 408 translated files. All 790 source code blocks remain unchanged in each language.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-12T19:40:56.054419Z	f873893	PR opened
🔒 Security Review	✅ Completed 2026-09-12T19:45:18.168315Z	f873893	PR opened

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