Feedback from Chrome store: translate context menus

[esokullu]

“As a Chinese user, for example, when I select a paragraph on X today and ask WebBrain to explain it, clicking “?” only shows options in English, such as “explain” and “Quiz me.” WebBrain has clearly recognized that I am a Chinese user, so could these options be displayed directly in Chinese? This causes the system to automatically respond in English after I click “explain,” and I have to ask it to answer in Chinese, after which it translates the response again. This wastes my tokens and is really not worthwhile.”

SO.. we need to translate context menus to the selected language

[esokullu]

I'm not sure if it's technically feasible

[alectimison-maker]

This was generated by AI during triage.

I traced this against current main (9aa969c3). It is technically feasible, and the limitation is in extension-owned code rather than a browser/content-script restriction.

Root cause

There are two independent English-only layers:

1. The floating shortcut renders Summarize, Explain, Quiz me, etc. as hardcoded HTML in selection-shortcut.js. The native context menu repeats hardcoded titles in background.js.
2. buildSelectionPrompt() selects hardcoded English instructions from SELECTION_SHORTCUT_ACTIONS. Although the content script already reads wbLocale, it sends that language only for the translate action. For explain, summarize, and the other fixed actions, the model receives no requested response language.

A deterministic reproduction is:

buildSelectionPrompt('这里有 Electron 和 Tauri', 'explain', '', 'zh')

The resulting prompt still starts with Explain this selected text in plain language. and contains no instruction to answer in Chinese.

Suggested implementation

• Add the selection-surface labels, accessibility labels, placeholder, hide action, and toasts to the existing 23-locale catalog.
• Let the module background resolve those strings for wbLocale; the closed-shadow-DOM content script can request the resolved bundle by runtime message on startup and when wbLocale changes.
• Use the same resolver when creating native context-menu titles, and rebuild those menus after a locale change.
• Propagate the interface locale for every selection action, not only translate, and add an explicit trusted response-language instruction for fixed actions. Keep action IDs structural and language-neutral.
• Preserve the existing <untrusted_page_content> wrapper and selection_only source-grounding behavior unchanged; localization must not weaken the prompt-injection boundary.
• Fall back per key to English and mirror Chrome/Firefox behavior.

Regression coverage should verify at least that wbLocale=zh localizes both menu surfaces and that explain asks for a Chinese response, while English fallback, translation targets, action normalization, and untrusted-content wrapping remain intact.