feat(admin): 添加 S3 兼容存储备份功能

- 新增 S3 配置管理页面，支持 AWS S3、Cloudflare R2、MinIO 等兼容存储
- 实现 S3 客户端工具类，使用 aws4fetch 进行签名和上传
- 添加手动触发备份功能，将评论、配置和统计数据打包为 JSON 上传至 S3
- 在管理后台数据管理页面集成 S3 配置表单和备份操作按钮
- 新增相关 API 端点用于获取/保存 S3 配置及触发备份

cwd-api/src/api/admin/s3Settings.ts

@@ -0,0 +1,38 @@
+import { Context } from 'hono';
+import { Bindings } from '../../bindings';
+import { loadS3Settings, saveS3Settings } from '../../utils/s3Settings';
+
+export async function getS3Settings(c: Context<{ Bindings: Bindings }>) {
+	try {
+		const settings = await loadS3Settings(c.env);
+		// Hide secret key for security in UI if needed, but usually user needs to edit it.
+		// For now, return it as is, or maybe mask it partially?
+		// User usually expects to see the inputs.
+		return c.json(settings);
+	} catch (e: any) {
+		return c.json({ message: e.message || '加载 S3 配置失败' }, 500);
+	}
+}
+
+export async function updateS3Settings(c: Context<{ Bindings: Bindings }>) {
+	try {
+		const body = await c.req.json();
+		const endpoint = typeof body.endpoint === 'string' ? body.endpoint.trim() : '';
+		const accessKeyId = typeof body.accessKeyId === 'string' ? body.accessKeyId.trim() : '';
+		const secretAccessKey = typeof body.secretAccessKey === 'string' ? body.secretAccessKey.trim() : '';
+		const bucket = typeof body.bucket === 'string' ? body.bucket.trim() : '';
+		const region = typeof body.region === 'string' ? body.region.trim() : 'auto';
+
+		await saveS3Settings(c.env, {
+			endpoint,
+			accessKeyId,
+			secretAccessKey,
+			bucket,
+			region,
+		});
+
+		return c.json({ message: '保存成功' });
+	} catch (e: any) {
+		return c.json({ message: e.message || '保存失败' }, 500);
+	}
+}

cwd-api/src/api/admin/triggerS3Backup.ts

@@ -0,0 +1,54 @@
+import { Context } from 'hono';
+import { Bindings } from '../../bindings';
+import { loadS3Settings } from '../../utils/s3Settings';
+import { S3Client } from '../../utils/s3';
+import { getConfigs } from './exportConfig';
+import { getStatsData } from './exportStats';
+
+export async function triggerS3Backup(c: Context<{ Bindings: Bindings }>) {
+	try {
+		// 1. Load S3 Settings
+		const settings = await loadS3Settings(c.env);
+		if (!settings.endpoint || !settings.bucket || !settings.accessKeyId || !settings.secretAccessKey) {
+			return c.json({ message: 'S3 配置不完整，请先配置 S3 信息' }, 400);
+		}
+
+		// 2. Gather Backup Data (Logic from exportBackup.ts)
+		const { results: comments } = await c.env.CWD_DB.prepare('SELECT * FROM Comment ORDER BY priority DESC, created DESC').all();
+		const configs = await getConfigs(c.env);
+		const stats = await getStatsData(c.env);
+
+		const backupData = {
+			version: '1.0',
+			timestamp: Date.now(),
+			comments: comments,
+			settings: configs,
+			page_stats: stats.page_stats,
+			page_visit_daily: stats.page_visit_daily,
+			likes: stats.likes,
+		};
+
+		const jsonString = JSON.stringify(backupData, null, 2);
+		const dateStr = new Date().toISOString().split('T')[0];
+		const fileName = `cwd-backup-${dateStr}-${Date.now()}.json`;
+
+		// 3. Upload to S3
+		const s3 = new S3Client({
+			endpoint: settings.endpoint,
+			accessKeyId: settings.accessKeyId,
+			secretAccessKey: settings.secretAccessKey,
+			bucket: settings.bucket,
+			region: settings.region,
+		});
+
+		await s3.putObject(fileName, jsonString);
+
+		return c.json({
+			message: '备份成功',
+			file: fileName,
+		});
+	} catch (e: any) {
+		console.error('S3 Backup Error:', e);
+		return c.json({ message: e.message || 'S3 备份失败' }, 500);
+	}
+}