Fix/post list excerpt rendering (#41)

* feat: use excerpts in post lists

* chore: made testing less noisy

---------

Co-authored-by: hugo <hugoms@me.com>

tests/engine/PageRenderer.renderPostList.test.ts

@@ -1,11 +1,31 @@
 import { describe, expect, it } from 'vitest';
 import { PageRenderer, type HtmlRewriteContext } from '../../src/main/engine/PageRenderer';
+import type { PostData } from '../../src/main/engine/PostEngine';
 
 const rewriteContext: HtmlRewriteContext = {
   canonicalPostPathBySlug: new Map<string, string>(),
   canonicalMediaPathBySourcePath: new Map<string, string>(),
 };
 
+function makePost(overrides: Partial<PostData> = {}): PostData {
+  return {
+    id: overrides.id ?? 'post-1',
+    projectId: overrides.projectId ?? 'project-1',
+    title: overrides.title ?? 'Test Post',
+    slug: overrides.slug ?? 'test-post',
+    excerpt: overrides.excerpt,
+    content: overrides.content ?? 'Default body content.',
+    status: overrides.status ?? 'published',
+    author: overrides.author,
+    language: overrides.language ?? 'en',
+    createdAt: overrides.createdAt ?? new Date('2026-02-22T10:00:00Z'),
+    updatedAt: overrides.updatedAt ?? new Date('2026-02-22T10:00:00Z'),
+    publishedAt: overrides.publishedAt,
+    tags: overrides.tags ?? [],
+    categories: overrides.categories ?? [],
+  };
+}
+
 describe('PageRenderer.renderPostList', () => {
   it('renders base framework for empty day archive pages instead of returning empty html', async () => {
     const renderer = new PageRenderer(
@@ -31,4 +51,88 @@ describe('PageRenderer.renderPostList', () => {
     expect(html).toContain('<section class="post-list"');
     expect(html).toContain('<h1 class="archive-heading">Archive 22. February 2026</h1>');
   });
+
+  it('shows excerpt only for titled posts that have one, but keeps full body otherwise', async () => {
+    const renderer = new PageRenderer(
+      { getAllMedia: async () => [] },
+      {
+        getLinkedMediaDataForPost: async () => [],
+        setProjectContext: () => {},
+      },
+    );
+
+    const html = await renderer.renderPostList([
+      makePost({
+        id: 'with-excerpt',
+        slug: 'with-excerpt',
+        title: 'With Excerpt',
+        excerpt: 'EXCERPT ONLY CONTENT',
+        content: 'FULL BODY SHOULD NOT APPEAR',
+      }),
+      makePost({
+        id: 'without-excerpt',
+        slug: 'without-excerpt',
+        title: 'Without Excerpt',
+        content: 'FULL BODY WITHOUT EXCERPT',
+      }),
+      makePost({
+        id: 'aside-post',
+        slug: 'aside-post',
+        title: 'Hidden Title',
+        excerpt: 'ASIDE EXCERPT SHOULD NOT APPEAR',
+        content: 'ASIDE FULL BODY SHOULD APPEAR',
+        categories: ['aside'],
+      }),
+    ], rewriteContext, {
+      archiveGrouping: false,
+      routeKind: 'non-date',
+      basePathname: '/',
+      page_title: 'Test Blog',
+      language: 'en',
+      menu_items: [],
+      categorySettings: {
+        aside: {
+          renderInLists: true,
+          showTitle: false,
+        },
+      },
+    });
+
+    expect(html).toContain('EXCERPT ONLY CONTENT');
+    expect(html).not.toContain('FULL BODY SHOULD NOT APPEAR');
+    expect(html).toContain('FULL BODY WITHOUT EXCERPT');
+    expect(html).toContain('ASIDE FULL BODY SHOULD APPEAR');
+    expect(html).not.toContain('ASIDE EXCERPT SHOULD NOT APPEAR');
+  });
+});
+
+describe('PageRenderer.renderSinglePost', () => {
+  it('always renders the full body even when an excerpt exists', async () => {
+    const renderer = new PageRenderer(
+      { getAllMedia: async () => [] },
+      {
+        getLinkedMediaDataForPost: async () => [],
+        setProjectContext: () => {},
+      },
+    );
+
+    const html = await renderer.renderSinglePost(
+      makePost({
+        id: 'single-post',
+        slug: 'single-post',
+        title: 'Single Post',
+        excerpt: 'SINGLE EXCERPT SHOULD NOT REPLACE BODY',
+        content: 'SINGLE FULL BODY SHOULD APPEAR',
+      }),
+      rewriteContext,
+      {
+        page_title: 'Single Post',
+        language: 'en',
+        menu_items: [],
+      },
+    );
+
+    expect(html).toContain('SINGLE FULL BODY SHOULD APPEAR');
+    expect(html).not.toContain('SINGLE EXCERPT SHOULD NOT REPLACE BODY');
+  });
 });