feat(i18n): expand catalog runtime and developer tooling

- add Intl-backed locale definitions, formatters, catalog loaders, and runtime hooks\n- compile hashed production catalogs from package-scoped catalog sources\n- drive Lingui extraction and compilation directly from project JSON config\n- redesign the devtool with localized controls, draggable persistence, settings, navigation, copy actions, ANSI output, and fullscreen support\n- extend repository APIs, CLI coverage, documentation, and runtime tests

packages/i18n/src/devtool/app/app.tsx

@@ -40,19 +40,26 @@ export function DevtoolApp() {
     )
   }
 
-  const locale = state.project.locales[0]
+  const locale =
+    state.project.locales.find(
+      (locale) => locale !== state.project.sourceLocale
+    ) ?? state.project.sourceLocale
 
-  if (!locale) {
+  if (!state.project.locales.includes(locale)) {
     return (
       <main className="devtool-app__state">
-        Add a locale with <code>workspace-i18n new &lt;locale&gt;</code>.
+        Add a target locale with <code>workspace-i18n new &lt;locale&gt;</code>.
       </main>
     )
   }
 
   return (
     <I18nProvider locale={locale} locales={state.project.locales}>
-      <I18nDevtool defaultOpen mode="standalone" />
+      <I18nDevtool
+        defaultOpen
+        mode="standalone"
+        sourceLocale={state.project.sourceLocale}
+      />
     </I18nProvider>
   )
 }