feat: display multilingual release notes in version management

- Support Simplified Chinese, Traditional Chinese, English, and Japanese
- Follow the UI language and show a notice when notes are unavailable
- Avoid language and content fallbacks
- Generate Release bodies and update manifests from per-version Markdown
- Add collapsible notes, publication dates, and links to full releases
- Test publishing, legacy manifest compatibility, and localized rendering

scripts/release-notes.mjs

@@ -0,0 +1,63 @@
+import { readFile, writeFile } from 'node:fs/promises';
+import { join, resolve } from 'node:path';
+import { pathToFileURL } from 'node:url';
+import { validateAppVersion } from './version.mjs';
+
+export const releaseNotesLanguages = [
+  { locale: 'zh-CN', label: '简体中文', missing: '暂未提供该版本的简体中文更新说明。' },
+  { locale: 'zh-TW', label: '繁體中文', missing: '暫未提供此版本的繁體中文更新說明。' },
+  { locale: 'en', label: 'English', missing: 'Release notes for this version are not available in English.' },
+  { locale: 'ja', label: '日本語', missing: 'このバージョンの日本語の更新内容はありません。' },
+];
+
+// Only explicitly authored translations are published. Missing languages stay missing.
+export async function resolveReleaseNotes({ root = process.cwd(), tag }) {
+  const version = validateAppVersion(String(tag ?? '').trim().replace(/^v/, ''), 'release tag');
+  const directory = join(root, 'docs', 'release-notes', `v${version}`);
+  const notes = {};
+  for (const { locale } of releaseNotesLanguages) {
+    try {
+      const text = (await readFile(join(directory, `${locale}.md`), 'utf8')).trim();
+      if (text) notes[locale] = `${text}\n`;
+    } catch (error) {
+      if (error.code !== 'ENOENT') throw error;
+    }
+  }
+  return notes;
+}
+
+export function validateReleaseNotes(notes) {
+  if (!notes || typeof notes !== 'object' || Array.isArray(notes)) {
+    throw new Error('Release notes must be an object keyed by locale');
+  }
+  for (const [locale, text] of Object.entries(notes)) {
+    if (!releaseNotesLanguages.some((language) => language.locale === locale)
+      || typeof text !== 'string' || !text.trim()) {
+      throw new Error(`Invalid release notes for locale: ${locale}`);
+    }
+  }
+}
+
+export function releaseNotesBody(notes) {
+  validateReleaseNotes(notes);
+  return `${releaseNotesLanguages.map(({ locale, label, missing }) => (
+    `# ${label}\n\n${notes[locale]?.trim() || missing}`
+  )).join('\n\n---\n\n')}\n`;
+}
+
+async function main() {
+  const args = new Map();
+  for (let index = 2; index < process.argv.length; index += 2) {
+    args.set(process.argv[index], process.argv[index + 1]);
+  }
+  if (!args.get('--output') || !args.get('--body-output')) {
+    throw new Error('--output and --body-output are required');
+  }
+  const notes = await resolveReleaseNotes({ tag: args.get('--tag') });
+  await writeFile(resolve(args.get('--output')), `${JSON.stringify(notes, null, 2)}\n`, 'utf8');
+  await writeFile(resolve(args.get('--body-output')), releaseNotesBody(notes), 'utf8');
+}
+
+if (process.argv[1] && import.meta.url === pathToFileURL(resolve(process.argv[1])).href) {
+  await main();
+}