✨ feat(i18n): 完善多模块多语言适配与发版验证

扩展前后端多语言文案与共享词典。增加多模块 i18n 回归测试与 guard。收口外部 SQL 菜单和弹窗多语言文案。

frontend/src/components/SidebarBatchObjectLoadFeedback.i18n.test.ts

@@ -0,0 +1,43 @@
+import { readFileSync } from 'node:fs';
+import { describe, expect, it } from 'vitest';
+
+const source = readFileSync(new URL('./Sidebar.tsx', import.meta.url), 'utf8');
+const locales = ['zh-CN', 'zh-TW', 'en-US', 'ja-JP', 'de-DE', 'ru-RU'] as const;
+const requiredKeys = [
+  'sidebar.message.load_database_list_failed',
+  'sidebar.message.load_table_list_failed',
+] as const;
+
+const extractBatchObjectLoadBlock = (): string => {
+  const start = source.indexOf('const loadDatabasesForBatch = async');
+  const end = source.indexOf('const handleConnectionChange = async', start);
+  expect(start).toBeGreaterThanOrEqual(0);
+  expect(end).toBeGreaterThan(start);
+  return source.slice(start, end);
+};
+
+const placeholders = (value: string): string[] => [...value.matchAll(/\{\{(\w+)\}\}/g)]
+  .map((match) => match[1])
+  .sort();
+
+describe('Sidebar batch object load feedback i18n', () => {
+  it('localizes batch database and object list loading failure wrappers', () => {
+    const block = extractBatchObjectLoadBlock();
+
+    expect(block).not.toContain("'获取数据库列表失败: ' + res.message");
+    expect(block).not.toContain("'获取表列表失败: ' + res.message");
+    expect(block).toContain("t('sidebar.message.load_database_list_failed'");
+    expect(block).toContain("t('sidebar.message.load_table_list_failed'");
+    expect(block).toContain('error: res.message');
+  });
+
+  it('keeps batch object load feedback keys available with stable placeholders', () => {
+    locales.forEach((locale) => {
+      const catalog = JSON.parse(readFileSync(new URL(`../../../shared/i18n/${locale}.json`, import.meta.url), 'utf8')) as Record<string, string>;
+      requiredKeys.forEach((key) => {
+        expect(catalog[key], `${locale}:${key}`).toBeTruthy();
+        expect(placeholders(catalog[key])).toEqual(['error']);
+      });
+    });
+  });
+});