feat(i18n): add Lingui runtime and development tooling

- add SSR-safe I18nProvider, Translate, locale hooks, catalog activation, and typed runtime APIs

- add consumer-owned Lingui configuration helpers and a CLI for locale creation, extraction, compilation, and project discovery

- add catalog read/write services plus a Vite development API plugin scoped to each consuming application

- add the portal-based I18nDevtool, message editor, dark-theme tracking, and standalone Message Studio

- document the consumer workflow and cover runtime, configuration, catalog, CLI, and Devtool behavior with tests

packages/i18n/src/runtime/context.ts

@@ -0,0 +1,13 @@
+import * as React from "react"
+import type { AllMessages } from "@lingui/core"
+
+import type { LocaleDefinition } from "./types"
+
+export interface I18nRuntimeContextValue {
+  catalogs: AllMessages
+  locale: string
+  locales: readonly LocaleDefinition[]
+}
+
+export const I18nRuntimeContext =
+  React.createContext<I18nRuntimeContextValue | null>(null)