fix: project got corrupted sometimes

tests/engine/MediaEngine.test.ts

@@ -229,6 +229,16 @@ describe('MediaEngine', () => {
       expect(mediaEngine.getProjectContext()).toBe('my-blog');
     });
 
+    it('should avoid duplicate context log when context is unchanged', () => {
+      const consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
+
+      mediaEngine.setProjectContext('same-project', '/tmp/data', '/tmp/internal');
+      mediaEngine.setProjectContext('same-project', '/tmp/data', '/tmp/internal');
+
+      expect(consoleLogSpy).toHaveBeenCalledTimes(1);
+      consoleLogSpy.mockRestore();
+    });
+
     it('should allow changing project context multiple times', () => {
       mediaEngine.setProjectContext('blog-1');
       expect(mediaEngine.getProjectContext()).toBe('blog-1');

tests/engine/MetaEngine.test.ts

@@ -48,6 +48,27 @@ vi.mock('fs/promises', () => ({
       throw err;
     }
   }),
+  rename: vi.fn(async (oldPath: string, newPath: string) => {
+    const normalizedOldPath = oldPath.replace(/\\/g, '/');
+    const normalizedNewPath = newPath.replace(/\\/g, '/');
+    const content = mockFiles.get(normalizedOldPath);
+    if (content === undefined) {
+      const err = new Error(`ENOENT: no such file or directory, rename '${oldPath}' -> '${newPath}'`) as NodeJS.ErrnoException;
+      err.code = 'ENOENT';
+      throw err;
+    }
+    mockFiles.set(normalizedNewPath, content);
+    mockFiles.delete(normalizedOldPath);
+  }),
+  unlink: vi.fn(async (filePath: string) => {
+    const normalizedPath = filePath.replace(/\\/g, '/');
+    if (!mockFiles.has(normalizedPath)) {
+      const err = new Error(`ENOENT: no such file or directory, unlink '${filePath}'`) as NodeJS.ErrnoException;
+      err.code = 'ENOENT';
+      throw err;
+    }
+    mockFiles.delete(normalizedPath);
+  }),
 }));
 
 // Mock electron app
@@ -986,6 +1007,27 @@ describe('MetaEngine', () => {
       expect(metaEngine.isInitialized()).toBe(false);
     });
 
+    it('should keep initialized flag when project context is unchanged', async () => {
+      await metaEngine.syncOnStartup();
+      expect(metaEngine.isInitialized()).toBe(true);
+
+      metaEngine.setProjectContext('test-project');
+      expect(metaEngine.isInitialized()).toBe(true);
+    });
+
+    it('should de-duplicate concurrent syncOnStartup calls', async () => {
+      const collectTagsSpy = vi.spyOn(metaEngine as unknown as {
+        collectTagsFromPosts: () => Promise<string[]>;
+      }, 'collectTagsFromPosts');
+
+      await Promise.all([
+        metaEngine.syncOnStartup(),
+        metaEngine.syncOnStartup(),
+      ]);
+
+      expect(collectTagsSpy).toHaveBeenCalledTimes(1);
+    });
+
     it('should use custom dataDir when provided in setProjectContext', () => {
       const customDataDir = path.join('custom', 'data', 'path');
       metaEngine.setProjectContext('project-with-custom-dir', customDataDir);

tests/engine/PostMediaEngine.test.ts

@@ -154,6 +154,16 @@ describe('PostMediaEngine', () => {
       expect(true).toBe(true);
     });
 
+    it('should avoid duplicate context log when context is unchanged', () => {
+      const consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
+
+      engine.setProjectContext('same-project');
+      engine.setProjectContext('same-project');
+
+      expect(consoleLogSpy).toHaveBeenCalledTimes(1);
+      consoleLogSpy.mockRestore();
+    });
+
     it('should allow changing project context multiple times', () => {
       engine.setProjectContext('blog-1');
       engine.setProjectContext('blog-2');

tests/engine/PreviewServer.test.ts

@@ -339,6 +339,48 @@ describe('PreviewServer', () => {
     expect(lightboxLoadingImageResponse.headers.get('content-type')).toContain('image/gif');
   });
 
+  it('does not set project context or run startup sync for static asset requests', async () => {
+    const postEngine = makeEngine([makePost()]);
+    const mediaEngine = {
+      setProjectContext: vi.fn(),
+      async getAllMedia() {
+        return [];
+      },
+    };
+    const postMediaEngine = makePostMediaEngine({});
+    const syncOnStartup = vi.fn(async () => undefined);
+    const settingsEngine = {
+      setProjectContext: vi.fn(),
+      isInitialized: vi.fn(() => false),
+      syncOnStartup,
+      async getProjectMetadata() {
+        return { maxPostsPerPage: 50 };
+      },
+    };
+    const menuEngine = makeMenuEngine({ items: [] });
+
+    server = new PreviewServer({
+      postEngine,
+      mediaEngine: mediaEngine as any,
+      postMediaEngine,
+      settingsEngine: settingsEngine as any,
+      menuEngine,
+      getActiveProjectContext: async () => ({ projectId: 'default', dataDir: '/tmp/default' }),
+    });
+
+    await server.start(0);
+
+    const response = await fetch(`${server.getBaseUrl()}/assets/pico.min.css`);
+    expect(response.status).toBe(200);
+
+    expect(postEngine.setProjectContext).not.toHaveBeenCalled();
+    expect(mediaEngine.setProjectContext).not.toHaveBeenCalled();
+    expect(postMediaEngine.setProjectContext).not.toHaveBeenCalled();
+    expect(settingsEngine.setProjectContext).not.toHaveBeenCalled();
+    expect(menuEngine.setProjectContext).not.toHaveBeenCalled();
+    expect(syncOnStartup).not.toHaveBeenCalled();
+  });
+
   it('renders tag_cloud macro with normalized tag usage and tag archive links', async () => {
     const posts = [
       makePost({