Implement upsert label flow and use-based mark gone handling

src/components/app-shell.js

@@ -1,12 +1,22 @@
 import { navBar } from './nav-bar.js';
 
-export function appShell(appName) {
+export function appShell(appName, appVersion, runtimeMode) {
+  const currentYear = new Date().getFullYear();
+
   return `
     <div class="app-shell d-flex flex-column min-vh-100">
       <div id="app-nav">
         ${navBar(appName)}
       </div>
       <main id="route-view" class="flex-grow-1"></main>
+      <footer class="app-footer border-top mt-auto py-3">
+        <div class="container-xxl d-flex flex-column flex-md-row justify-content-between align-items-md-center gap-1 small">
+          <div>&copy; ${currentYear} AKLARO</div>
+          <div class="text-body-secondary">
+            ${appName} v${appVersion} • ${runtimeMode} mode • PWA frontend for Tryton kitchen
+          </div>
+        </div>
+      </footer>
       <div class="toast-stack" x-data="alertsData()">
         <template x-for="alert in alerts" :key="alert.id">
           <div class="toast show align-items-center border-0 mb-2 text-bg-dark" role="status">