feat(app): I18n support (only chinese currently)

[Eric-Guo]

Implement / Closes: #7170, #6326, #2357

app/desktop only, console/terminal suggest don't do i18n support and not include in this PR

Cmd+Shift+l to switch the language or Cmd+P and type 'language', no UI button added yet.

Windows:

MacOS

[github-actions[bot]]

Hey! Your PR title feat(app) I18n support (only chinese currently) doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions[bot]]

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

Potential Duplicate PRs Found:

1. PR #7290 - feat(app): add i18n internationalization support

   • https://github.com/anomalyco/opencode/pull/7290
   • This PR has nearly identical title and scope as PR #9190, both implementing i18n support

2. PR #6776 - feat(i18n): add internationalization with Korean translations

   • https://github.com/anomalyco/opencode/pull/6776
   • Related work on i18n infrastructure with different language focus

3. PR #1581 - feat: implement comprehensive Chinese translation support

   • https://github.com/anomalyco/opencode/pull/1581
   • Specifically targets Chinese translations, overlapping with PR #9190's scope

Note: PR #7290 appears to be the most directly related, as it has the same feature (i18n support) and possibly the same implementation intent as the current PR #9190.

[github-actions[bot]]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[adamdotdevin]

@Eric-Guo mind adding some screenshots? What is the mechanism for switching langauges? Is there any auto-detection?

[Eric-Guo]

screenshot add, you can using Cmd+Shift+l to switch the language or Cmd+P and type 'language'.

The translation is relative complete.

No any auto-detection and no other 4 languages😎, but I think it can be add later without too much conflict here.

[Eric-Guo]

do in dev already.