Localization

Ruphish currently provides English and German interface text. Translation catalogs live in crates/ruphish-ui/locales/en.json and de.json; the UI build uses leptos_i18n to generate checked keys. English is the default and fallback.

Add or change text

1. Find the feature’s existing keys and shared terminology. Add equivalent entries to both catalogs instead of embedding a literal in a view.
2. Preserve interpolation names and the intent of action, field, help, and error text. Translate the task meaning rather than copying English word order.
3. Use the existing localization context and helpers: tr! for reactive view text, trs! for shared control labels, and t_string! with a captured context in callbacks or reactive computations.
4. Run the locale/functional checks and affected WASM checks from validation. Review the changed screens in both languages, including longer labels and wrapped controls.

Backend error codes remain stable machine identifiers. Translate them in the response handler instead of localizing server contracts. Already displayed error strings do not automatically change when the interface language changes.

Editor text uses the browser editor’s translation integration in web/editor-i18n.mjs; update it when changing editor-specific labels. Adding a new supported language also needs the locale inventory, preference validation, picker, and editor behavior reviewed, not only a new JSON file.

Keep three preferences independent

Preference	Controls	Example
Interface language	Navigation, labels, help, and translated errors	German
Formatting locale	Numeric date order, separators, and hour cycle	zh-CN
IANA time zone	Conversion from stored instants to civil time	Europe/Berlin

Account preferences also include show_utc_offset. A null override means follow the current browser default, not a saved snapshot of browser detection. Preferences are persisted by account and revalidated through browser session lifecycle. Container/server locale does not choose browser presentation.

/auth/session supplies browser state; GET/PUT /internal/preferences read or replace self-service preferences. These require the browser session/CSRF boundary and reject API-key access and impersonated preference changes. They are not public integration endpoints. Saving preferences does not change authentication generations.

Dates and schedules

Use domain date/time conversion and the shared browser formatter. Preserve exact UTC instants when the user leaves a filter unchanged. A display-preference change must not reschedule an existing campaign. New local-time input follows the shared daylight-saving resolution rules; do not add a different parser in one feature.

The formatting picker uses the vendored CLDR locale inventory filtered by browser Intl support and domain validation. Picker examples, preview, and application timestamps should use the same formatting path. Test language changes, browser-default resets, invalid/absent browser zones, repeated local times, and long localized labels where affected.