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/devtool/api-client.ts

@@ -0,0 +1,31 @@
+export type DevtoolAction = "compile" | "extract"
+
+interface ApiError {
+  error?: string
+}
+
+export async function requestDevtoolJson<T>(
+  url: string,
+  init?: RequestInit
+): Promise<T> {
+  const response = await fetch(url, init)
+  const body = (await response.json()) as T & ApiError
+
+  if (!response.ok) {
+    throw new Error(body.error ?? `Request failed with ${response.status}.`)
+  }
+
+  return body
+}
+
+export async function runDevtoolAction(
+  action: DevtoolAction,
+  baseUrl = "/__i18n"
+) {
+  const normalizedBaseUrl = baseUrl.replace(/\/+$/, "")
+
+  return requestDevtoolJson<{ output: string }>(
+    `${normalizedBaseUrl}/actions/${action}`,
+    { method: "POST" }
+  )
+}