feat: add built-in Arabic localization

[ezAldinWaez]

Description

This PR adds the built-in Arabic (ar) localization file following the BCP 47 IETF language tag standard.

Changes:

1. Created src/resources/language/_language-ar.yml duplicating all keys from the _language.yml default.
2. Verified exact key count parity (111 keys) with the English fallback to ensure flawless UI operations.
3. Used standard formal Arabic Technical terms (MSA) for both scientific/manuscript contexts (e.g., references, appendices, footnotes) and programming/UI components (e.g., source code, listings, callouts etc.).
4. Added _language-ar.yml directly to the supported language table in src/resources/language/README.md.

Testing

• Locally rendered a .qmd sample file with lang: ar to ensure the correct application of key translations across callouts, categories, and cross-references.

Checklist

• filed a contributor agreement. (📝 Note: I am ready to sign, but the current PDF links are broken as reported in Broken Contributor Agreement PDF links (404) across repository onboarding files #14388. I have also reached out to jj@rstudio.com).
• referenced the GitHub issue this PR closes (N/A)
• updated the appropriate changelog in the PR (N/A)
• ensured the present test suite passes
• added new tests
• created a separate documentation PR in Quarto's website repo and linked it to this PR

[Copilot]

Pull request overview

Adds built-in Arabic (ar) localization resources to Quarto’s bundled language pack, and documents Arabic as a supported built-in translation.

Changes:

• Added src/resources/language/_language-ar.yml with Arabic translations for the default language keys.
• Updated src/resources/language/README.md to include Arabic in the built-in translations table.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
src/resources/language/_language-ar.yml	Introduces Arabic translations for Quarto UI/crossref strings.
src/resources/language/README.md	Documents Arabic as a built-in localization option.

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[cscheid]

Thanks for the PR. I would like to avoid LLM-generated localizations, and I get the sense that your PR was opened with LLM help, especially given the unrelated change to Korean:

Can you please review this manually before we go any further?

[ezAldinWaez]

Can you please review this manually before we go any further?

honestly i did use some LLM help, but I did manually review every value in its context.

e.g: in Arabic, both 'الملاحق' and 'الملحقات' are acceptable translations for 'Appendices' (section-title-appendices), but 'الملاحق' is the most used in the academic context.

for the Korean change i'm not sure if it belongs here. happy to drop it if that’s cleaner.

[cscheid]

Yes, please either drop the Korean change or move it to a separate request.

For localization changes we try to get at least one independent review before merging. I'll get back to you on this.

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[cderv]

Thanks for the PR.

_language-ar.yml is missing 8 keys that exist in the base _language.yml on main. They were added recently, after the file was written, so they need an Arabic translation added to _language-ar.yml.

• skip-to-content
• navigation-site-label
• navigation-section-label
• navigation-toolbar-label
• navigation-page-label
• navigation-breadcrumbs-label
• scrollable-code-label
• scrollable-output-label

Could you add them ? For the five navigation-*-label ones, the translator rules are in the comment right above them in the base file, mainly that the value should not contain the word for "navigation" because screen readers already announce the landmark role.

quarto-cli/src/resources/language/_language.yml

Lines 87 to 97 in d58acfe

	# Landmark labels. Two rules for translators:
	# 1. Do not include the word "navigation". Screen readers announce the role after
	# the label (https://www.w3.org/WAI/ARIA/apg/practices/landmark-regions/).
	# 2. Use a noun, not a bare adjective. In several languages the adjective cannot
	# stand alone without the noun it agrees with.
	navigation-site-label: "Site"
	navigation-section-label: "Section"
	navigation-toolbar-label: "Toolbar"
	navigation-page-label: "Page"
	navigation-breadcrumbs-label: "Breadcrumbs"

I also have one question on a value. I don't speak Arabic, so I used AI tooling (Lara MCP) to help me review the file. We do that to be sure everything is fine. So I want to be upfront about that.

Everything else looked consistent to it, but it raised crossref-lem-title ("التوطئة"). It reads it back as "Preamble", while a direct translation of "Lemma" gave something closer to "sub-theorem" (مبرهنة فرعية). Is "التوطئة" the term usually used for a lemma in Arabic math writing ? It also noted that environment-remark-title ("الملاحظة") is the same word as callout-note-title ("ملاحظة"), so Remark and Note end up with the same label. That may well be fine, I just can't judge it.

These are questions only, not requests to change anything. I will ask a native speaker to do a final review of the translations before we merge.

Reviewing means verifying translatation makes sense with there English counterpart in https://github.com/quarto-dev/quarto-cli/blob/main/src/resources/language/_language.yml

[omar-rs]

"التنويه" might be a more accurate term for this

[cderv]

Thank you. Adding the suggestion below directly for @ezAldinWaez to take into account

Suggested change

	section-title-citation: "الاستشهاد"
	section-title-citation: "التنويه"