feat: integrate Pi backend and Pi Web

pi-web/lib/i18n/registry.ts

@@ -0,0 +1,43 @@
+import { enLocale } from "./messages/en";
+import { zhCNLocale } from "./messages/zh-CN";
+import type { Locale, LocalePlugin } from "./types";
+
+const localePlugins = new Map<string, LocalePlugin>();
+
+/** 注册一个语言包；重复注册会抛出异常，避免静默覆盖翻译。 */
+export function registerLocale(plugin: LocalePlugin): void {
+  if (!plugin.id.trim()) throw new Error("Locale id must not be empty");
+  if (localePlugins.has(plugin.id)) throw new Error(`Locale already registered: ${plugin.id}`);
+  localePlugins.set(plugin.id, plugin);
+}
+
+/**
+ * 根据标识获取已注册的语言包。
+ * @param id 要查询的语言标识
+ * @returns 已注册的语言包，不存在时返回 undefined
+ */
+export function getLocalePlugin(id: string): LocalePlugin | undefined {
+  return localePlugins.get(id);
+}
+
+/** 获取当前已注册语言的稳定顺序列表。 */
+export function getSupportedLocales(): string[] {
+  return [...localePlugins.keys()];
+}
+
+/**
+ * 将浏览器语言列表解析为 Pi Web 内置语言。
+ * @param languages 浏览器按优先级排列的语言列表
+ * @returns 匹配的内置语言，无法匹配时返回英语
+ */
+export function resolveBrowserLocale(languages: readonly string[]): Locale {
+  for (const language of languages) {
+    const normalized = language.toLowerCase();
+    if (normalized === "en" || normalized.startsWith("en-")) return "en";
+    if (normalized === "zh" || normalized.startsWith("zh-")) return "zh-CN";
+  }
+  return "en";
+}
+
+registerLocale(enLocale);
+registerLocale(zhCNLocale);