Apply typewriter/editorial UI style using system fonts only

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

webapp/src/components/app-shell.ts

@@ -7,7 +7,7 @@ export class AppShell extends HTMLElement {
   connectedCallback(): void {
     this.innerHTML = `
       <nav>
-        <a href="/days" id="nav-days">Tage</a>
+        <a href="/days" id="nav-days">Pamietnik</a>
         <button id="nav-logout">Abmelden</button>
       </nav>
       <main id="outlet"></main>