This PR changes the avatar placeholder letter font-weight to medium. I also updated the story to use a symmetric letter “E” instead of “L”, so that it is easier to spot alignment problems. Before : <img width="347" alt="Capture d’écran 2025-07-01 à 15 51 57" src="https://github.com/user-attachments/assets/b622083e-b9a8-45a9-9956-a15c0cb3508a" /> After : <img width="257" alt="Capture d’écran 2025-07-01 à 15 53 29" src="https://github.com/user-attachments/assets/e491af60-cfce-486d-9ee0-6bb4dff0f022" />