feat(ui): add alternative (full) picture for project cover and support for distinct cover (all projects page) and header img (single project page)

Author: davide-beltrame

_layouts/project.html

@@ -15,7 +15,7 @@
           <article class="article">
 
             <div class="post-img">
-              <img src="{{ page.cover }}" alt="{{ page.title }}">
+              <img src="{{ page.header_image | default: page.cover }}" alt="{{ page.title }}">
             </div>
 
             <h2 id="project-title" class="title text-center">{{ page.title }}</h2>

_projects/llm-validity.md

@@ -3,7 +3,8 @@ title: "LLM validity via enhanced conformal prediction: conditional guarantees,
 type: Research
 status: completed
 date: 2026-02-07
-cover: /assets/img/proj/llm_validity_cropped.png
+cover: /assets/img/proj/llm_validity.png
+header_image: /assets/img/proj/llm_validity_cropped.png
 authors:
   - name: "Davide Beltrame"
     avatar: "/assets/img/team/davide_beltrame.jpg"