feat(EnvelopeLocked): Timer mit CSS-Konfiguration und Javascript-Ereignis hinzugefügt.

- Ablauf über Home-Controller-Ansichtsdaten hinzugefügt

EnvelopeGenerator.Web/Views/Home/EnvelopeLocked.cshtml

@@ -1,4 +1,5 @@
 @using EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
+@using Newtonsoft.Json
 @{
     var nonce = _accessor.HttpContext?.Items["csp-nonce"] as string;
     var logo = _logoOpt.Value;
@@ -6,6 +7,7 @@
     var userCulture = ViewData["UserCulture"] as Culture;
     bool viaSms = ViewData["ViaSms"] is bool _viaSms && _viaSms;
     var accessCodeName = viaSms ? "smsCode" : "accessCode";
+    DateTime? expiration = ViewData["Expiration"] is DateTime _expiration ? _expiration : null;
 }
 <div class="page container py-4 px-4">
     <header class="text-center">
@@ -35,6 +37,10 @@
                             login
                         </span>
                     </button>
+                    @if (expiration is not null)
+                    {
+                    <div id="sms-timer" class="alert alert-primary" role="alert">00:00</div>
+                    }
                 </div>
             </form>
         </div>
@@ -52,4 +58,30 @@
             <p>@_localizer[viaSms ? WebKey.LockedSmsTfaFooterBody : WebKey.LockedFooterBody]</p>
         </details>
     </section>
-</div>
+</div>
+<script nonce="@nonce">
+    var expiration = new Date(@Html.Raw(JsonConvert.SerializeObject(expiration)));
+
+    const element = document.getElementById("sms-timer");
+
+    const interval = setInterval(function () {
+        var now = new Date();
+
+        var diffInMillis = expiration - now;
+
+        if (diffInMillis <= 0) {
+            element.textContent = "00:00";
+            clearInterval(interval);
+            return;
+        }
+
+        var minutes = Math.floor(diffInMillis / 1000 / 60);
+        var seconds = Math.floor((diffInMillis / 1000) % 60);
+
+        var formattedMinutes = minutes.toString().padStart(2, '0');
+        var formattedSeconds = seconds.toString().padStart(2, '0');
+
+        var remainingTime = `${formattedMinutes}:${formattedSeconds}`;
+        element.textContent = remainingTime;
+    }, 1000);
+</script>