feat: 新增 news 内容集合与 Zod schema（含单测）

package.json

@@ -14,6 +14,6 @@
     "zod": "^3.25.76"
   },
   "devDependencies": {
-    "vitest": "^4.1.10"
+    "vitest": "^3.2.7"
   }
 }

src/content.config.ts

@@ -0,0 +1,10 @@
+import { defineCollection } from 'astro:content';
+import { glob } from 'astro/loaders';
+import { newsSchema } from './content/schemas';
+
+const news = defineCollection({
+  loader: glob({ pattern: '**/*.md', base: './src/content/news' }),
+  schema: newsSchema,
+});
+
+export const collections = { news };

src/content/news/welcome.md

@@ -0,0 +1,7 @@
+---
+title: 官网基座启动
+date: 2026-07-23
+category: 公告
+---
+
+这是 Phase 0 技术验证的第一条新闻。内容编辑链路跑通后，客户可在 Sveltia CMS 自助新增。

src/content/schemas.ts

@@ -0,0 +1,7 @@
+import { z } from 'zod';
+
+export const newsSchema = z.object({
+  title: z.string(),
+  date: z.coerce.date(),
+  category: z.string().default('未分类'),
+});

tests/content-schema.test.ts

@@ -0,0 +1,28 @@
+import { describe, it, expect } from 'vitest';
+import { newsSchema } from '../src/content/schemas';
+
+describe('newsSchema', () => {
+  it('accepts valid frontmatter and coerces date', () => {
+    const parsed = newsSchema.parse({
+      title: '官网基座启动',
+      date: '2026-07-23',
+      category: '公告',
+    });
+    expect(parsed.title).toBe('官网基座启动');
+    expect(parsed.date).toEqual(new Date('2026-07-23'));
+    expect(parsed.category).toBe('公告');
+  });
+
+  it('defaults category to 未分类', () => {
+    const parsed = newsSchema.parse({ title: '测试', date: '2026-07-23' });
+    expect(parsed.category).toBe('未分类');
+  });
+
+  it('rejects missing title', () => {
+    expect(() => newsSchema.parse({ date: '2026-07-23' })).toThrow();
+  });
+
+  it('rejects missing date', () => {
+    expect(() => newsSchema.parse({ title: '测试' })).toThrow();
+  });
+});