feat(frontend): 控制台 next-intl 中英双语

接入无 URL 前缀的 zh-CN/en，顶栏与外观设置可切换语言；选择写入 cookie 后刷新生效。

frontend/scripts/check-i18n-keys.mjs

@@ -0,0 +1,36 @@
+import { readFileSync } from 'node:fs';
+import { resolve, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const root = resolve(dirname(fileURLToPath(import.meta.url)), '..');
+
+function flatten(obj, prefix = '') {
+  const keys = new Set();
+  for (const [key, value] of Object.entries(obj)) {
+    const path = prefix ? `${prefix}.${key}` : key;
+    if (value && typeof value === 'object' && !Array.isArray(value)) {
+      for (const child of flatten(value, path)) keys.add(child);
+    } else {
+      keys.add(path);
+    }
+  }
+  return keys;
+}
+
+const zh = JSON.parse(
+  readFileSync(resolve(root, 'messages/zh-CN.json'), 'utf8'),
+);
+const en = JSON.parse(readFileSync(resolve(root, 'messages/en.json'), 'utf8'));
+const zhKeys = flatten(zh);
+const enKeys = flatten(en);
+const onlyZh = [...zhKeys].filter((k) => !enKeys.has(k)).sort();
+const onlyEnFixed = [...enKeys].filter((k) => !zhKeys.has(k)).sort();
+
+if (onlyZh.length || onlyEnFixed.length) {
+  console.error('i18n key mismatch');
+  if (onlyZh.length) console.error('only in zh-CN:', onlyZh);
+  if (onlyEnFixed.length) console.error('only in en:', onlyEnFixed);
+  process.exit(1);
+}
+
+console.log(`i18n keys OK (${zhKeys.size} keys)`);

frontend/scripts/merge-i18n-fragments.mjs

@@ -0,0 +1,43 @@
+import { readFileSync, writeFileSync, readdirSync } from 'node:fs';
+import { resolve, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const root = resolve(dirname(fileURLToPath(import.meta.url)), '..');
+const fragmentsDir = resolve(root, 'messages/fragments');
+
+function deepMerge(target, source) {
+  for (const [key, value] of Object.entries(source)) {
+    if (
+      value &&
+      typeof value === 'object' &&
+      !Array.isArray(value) &&
+      target[key] &&
+      typeof target[key] === 'object' &&
+      !Array.isArray(target[key])
+    ) {
+      deepMerge(target[key], value);
+    } else {
+      target[key] = value;
+    }
+  }
+  return target;
+}
+
+function mergeLocale(locale) {
+  const mainPath = resolve(root, `messages/${locale}.json`);
+  const data = JSON.parse(readFileSync(mainPath, 'utf8'));
+  const suffix = `.${locale}.json`;
+  for (const name of readdirSync(fragmentsDir).sort()) {
+    if (!name.endsWith(suffix)) continue;
+    const frag = JSON.parse(
+      readFileSync(resolve(fragmentsDir, name), 'utf8'),
+    );
+    deepMerge(data, frag);
+    console.log(`merged ${name}`);
+  }
+  writeFileSync(mainPath, `${JSON.stringify(data, null, 2)}\n`);
+}
+
+mergeLocale('zh-CN');
+mergeLocale('en');
+console.log('fragments merged');