Modules: Localization

Internationalization and localization system (@rbx/localization). Status: Implemented (35 tests).

Purpose

• Multi-locale string registry with 18 supported locales.
• Template interpolation: "Welcome, {name}!".
• Pluralization with CLDR-style plural categories (zero, one, two, few, many, other).
• Namespace support for organizing translations by feature.
• Missing key fallback behavior (show key, empty, or bracket notation).

Core rules

• Translations are registered at startup; no per-player persistence.
• setLocale() changes the active locale globally (per-client).
• Missing keys fall back to defaultLocale before applying missing key behavior.
• Interpolation parameters are positional via {key} syntax.
• Plural forms are resolved based on count following CLDR rules.

Data model

• LocaleStrings — locale: LocaleCode, entries: Record<string, string | PluralEntry>
• PluralEntry — { zero?, one?, two?, few?, many?, other }

No DataStore persistence (locale preference is client-side).

Config/flags

• localization.defaultLocale (default "en")
• localization.logMissing — log warnings for missing translation keys
• localization.missingKeyBehavior — "key" | "empty" | "bracket"

Observability

• i18n.missing_key — translation key not found for active locale
• i18n.locale_changed — player changed locale