feat: localization service and frontend integration

- Add localization-service microservice (locale resolution, translations)
- Add frontend API routes /api/locale and /api/translations/[locale]
- Add LocalizationProvider and localization context
- Integrate localization into layout, EmptyChat, MessageInput components
- Update MICROSERVICES.md architecture docs
- Add localization-service to workspaces

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/localization-service/src/lib/resolveLocale.ts

@@ -0,0 +1,69 @@
+import type { GeoDeviceContext, LocalizationContext } from '../types.js';
+import {
+  resolveLocaleFromCountry,
+  normalizeAcceptLanguage,
+  getDefaultLocale,
+} from './countryToLocale.js';
+
+/**
+ * Определяет locale на основе geo-контекста.
+ * Приоритет: геопозиция > client.language > Accept-Language > fallback.
+ * Геопозиция первая — если пользователь в России, показываем русский.
+ */
+export function resolveLocale(ctx: GeoDeviceContext | null): LocalizationContext {
+  const fallback: LocalizationContext = {
+    locale: getDefaultLocale(),
+    language: getDefaultLocale(),
+    region: null,
+    countryCode: null,
+    timezone: null,
+    source: 'fallback',
+  };
+
+  if (!ctx) return fallback;
+
+  const geo = ctx.geo;
+  const acceptLang = normalizeAcceptLanguage(ctx.acceptLanguage);
+  const clientLang = ctx.client?.language
+    ? ctx.client.language.split('-')[0]?.toLowerCase()
+    : null;
+
+  // 1. Геопозиция (countryCode) — приоритет при определении по IP
+  if (geo?.countryCode) {
+    const locale = resolveLocaleFromCountry(geo.countryCode);
+    return {
+      locale,
+      language: locale,
+      region: geo.region ?? null,
+      countryCode: geo.countryCode,
+      timezone: geo.timezone ?? null,
+      source: 'geo',
+    };
+  }
+
+  // 2. Язык из client (браузер navigator.language)
+  if (clientLang) {
+    return {
+      locale: clientLang,
+      language: clientLang,
+      region: geo?.region ?? null,
+      countryCode: geo?.countryCode ?? null,
+      timezone: geo?.timezone ?? null,
+      source: 'client',
+    };
+  }
+
+  // 3. Accept-Language заголовок
+  if (acceptLang) {
+    return {
+      locale: acceptLang,
+      language: acceptLang,
+      region: geo?.region ?? null,
+      countryCode: geo?.countryCode ?? null,
+      timezone: geo?.timezone ?? null,
+      source: 'accept-language',
+    };
+  }
+
+  return fallback;
+}