fix: consistent handling of markdown between post preview and preview server

tests/renderer/components/EditorMarkdownPreview.test.ts

@@ -0,0 +1,21 @@
+import { describe, it, expect } from 'vitest';
+import { markdownToHtml } from '../../../src/renderer/components/Editor/Editor';
+
+describe('Editor markdown preview rendering', () => {
+  it('renders continuous blockquote lines as a single blockquote paragraph (CommonMark softbreak behavior)', () => {
+    const markdown = [
+      '> Georg Bauer',
+      '> Am Krug 40',
+      '> 48151 Münster',
+      '> eMail: gb at rfc1437.de',
+    ].join('\n');
+
+    const html = markdownToHtml(markdown, 'post-1');
+
+    expect((html.match(/<blockquote>/g) ?? []).length).toBe(1);
+    expect((html.match(/<p>/g) ?? []).length).toBe(1);
+    expect(html).not.toContain('<br');
+    expect(html).toContain('Georg Bauer');
+    expect(html).toContain('eMail: gb at rfc1437.de');
+  });
+});