docs: add Farsi (fa) translations

[amrear]

Issue for this PR

No linked issue. Adds Persian (Farsi, fa) localization. Related work: #34396 already adds the fa docs locale, all packages/web/src/content/docs/fa/ pages, the .opencode/glossary/fa.md glossary, and web UI string localization (packages/web/src/i18n/fa.json). This PR complements it by covering the README layer that #34396 does not: README.fa.md plus the فارسی link in the language bar of all 22 README files.

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Adds Farsi (Persian, fa) translations across the three localization layers OpenCode already uses:

• README: new README.fa.md plus the فارسی link added to the language bar in all 22 README files.
• Docs (Starlight): registered the fa locale (lang: fa-IR, dir: rtl) in packages/web/astro.config.mjs, and translated all 36 docs pages into packages/web/src/content/docs/fa/. Relative import/asset paths were adjusted one level deeper.
• Glossary: added .opencode/glossary/fa.md with preferred Farsi terms and RTL guidance.

Farsi is RTL, so the locale sets dir: "rtl" and Starlight renders the docs right-to-left. Technical artifacts (commands, flags, code, URLs, model IDs, config keys) are preserved verbatim per .opencode/command/translate.md.

How did you verify your code works?

• README.fa.md renders with the full language bar.
• Confirmed every root docs page has a fa/ counterpart and that config.mjs imports use ../../../../config.mjs.
• Locale entry validated against the existing locales shape in astro.config.mjs.

Screenshots / recordings

Not applicable (docs/markdown changes).

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Found a potentially related PR:

PR #34396: docs: add Persian (fa) docs site localization
#34396

This PR appears to be addressing the same feature—adding Farsi/Persian (fa) translations and localization to the docs site. It likely covers similar changes to the Astro config and docs pages in Farsi. This could be a duplicate effort or an earlier related attempt that may need to be consolidated.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍

[github-actions]

Automated PR Cleanup

Thank you for contributing to opencode.

Due to the high volume of PRs from users and AI agents, we periodically close older PRs using automated criteria so maintainers can focus review time on the most active and community-supported contributions.

This PR was closed because it matched the following cleanup criteria:

• The PR was created more than 1 month ago
• The PR had fewer than 2 positive reactions
• Positive reactions are counted as thumbs-up, heart, celebration, or rocket reactions on the PR

PRs created within the last month are not affected by this cleanup.

If you believe this PR was closed incorrectly, or if you are still actively working on it, please leave a comment explaining why it should be reopened. A maintainer can review and reopen it if appropriate.

Thanks again for taking the time to contribute.