chore: fix hugo deprecation warnings (hugo 0.167.0) (#604)

* chore: fix hugo deprecation warnings (hugo 0.165.0)

- Replace deprecated `.Language.LanguageName` with `.Language.Label` in navbar
- Replace deprecated `languageName` config key with `label` in exampleSite
- Add missing `ariaLanguage` i18n key (en, de, ar)
- Bump Hugo to 0.165.0 in CI, Netlify and devcontainer
- Raise theme min_version to 0.158.0 (required for Label/Locale/Direction)

Closes #601

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* chore: resolve sonarcloud findings in devcontainer and CI

- Quote shell variables in Dockerfile (docker:S6570)
- Enforce HTTPS-only downloads via curl --proto "=https" and drop wget (docker:S6506)
- Install apt packages with --no-install-recommends, sorted (docker:S6500, S7018)
- Run npm ci with --ignore-scripts in update-resources workflow (githubactions:S6505)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* chore: bump hugo to 0.167.0

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>