fix(pwa): BUG-005 chargement mobile via Cloudflare (SW network-first + no-cache)

frontend/index.html

@@ -5067,8 +5067,27 @@ curl -X POST https://votre-serveur.com/webhook \
         </div>
 
         <script>
-        // Force-kill stale Service Worker and reload fresh
-        (function(){if('serviceWorker'in navigator&&navigator.serviceWorker.controller){var reloaded=sessionStorage.getItem('_sw_killed');if(!reloaded){navigator.serviceWorker.getRegistrations().then(function(regs){regs.forEach(function(r){r.unregister()})});caches.keys().then(function(names){names.forEach(function(n){caches.delete(n)})});sessionStorage.setItem('_sw_killed','1');location.reload(true)}}else{sessionStorage.removeItem('_sw_killed')}})();
+        // One-time migration for devices stuck on the legacy service worker
+        // (cache-first with a fixed cache name). Deletes the old caches and
+        // triggers an update check; the new network-first SW then takes over.
+        // Keyed in localStorage so it never loops or re-runs on every session.
+        (function () {
+            if (!('serviceWorker' in navigator) || !('caches' in window)) return;
+            var MIGRATION_KEY = 'obsigate-sw-migration';
+            try {
+                if (localStorage.getItem(MIGRATION_KEY) === 'v2') return;
+                localStorage.setItem(MIGRATION_KEY, 'v2');
+            } catch (e) { return; }
+            caches.keys().then(function (names) {
+                return Promise.all(names.map(function (name) {
+                    return /^obsigate-(v1|offline-v1)$/.test(name) ? caches.delete(name) : null;
+                }));
+            }).then(function () {
+                return navigator.serviceWorker.getRegistration();
+            }).then(function (reg) {
+                if (reg) reg.update();
+            }).catch(function () { /* best effort */ });
+        })();
         </script>
         <script type="module" src="/static/js/app.js"></script>