fix: better test base

src/main/engine/MediaEngine.ts

@@ -4,6 +4,7 @@ import * as fs from 'fs/promises';
 import * as path from 'path';
 import * as crypto from 'crypto';
 import { eq } from 'drizzle-orm';
+import { app } from 'electron';
 import { getDatabase } from '../database';
 import { media, Media, NewMedia } from '../database/schema';
 import { taskManager, Task } from './TaskManager';
@@ -45,8 +46,6 @@ export class MediaEngine extends EventEmitter {
   }
 
   private getMediaDir(): string {
-    const { app } = require('electron');
-    const path = require('path');
     const userDataPath = app.getPath('userData');
     return path.join(userDataPath, 'projects', this.currentProjectId, 'media');
   }

src/main/engine/PostEngine.ts

@@ -92,21 +92,23 @@ export class PostEngine extends EventEmitter {
   }
 
   private async writePostFile(post: PostData): Promise<string> {
-    const metadata: PostMetadata = {
+    const metadata: Record<string, unknown> = {
       id: post.id,
       projectId: post.projectId,
       title: post.title,
       slug: post.slug,
-      excerpt: post.excerpt,
       status: post.status,
-      author: post.author,
       createdAt: post.createdAt.toISOString(),
       updatedAt: post.updatedAt.toISOString(),
-      publishedAt: post.publishedAt?.toISOString(),
       tags: post.tags,
       categories: post.categories,
     };
 
+    // Only add optional fields if they have values (gray-matter can't serialize undefined)
+    if (post.excerpt) metadata.excerpt = post.excerpt;
+    if (post.author) metadata.author = post.author;
+    if (post.publishedAt) metadata.publishedAt = post.publishedAt.toISOString();
+
     const postsDir = this.getPostsDir();
     await fs.mkdir(postsDir, { recursive: true });