feat: add resilient container restart controls

internal/web/templates/system.html

@@ -18,7 +18,7 @@
     {{if .SoftwareUpdate.ComposeSyncRequired}}<div class="update-inline-warning"><span>↻</span><p><strong>Compose einmal aktualisieren</strong><small>Der installierte Agent unterstützt die sichere Update-Basis noch nicht.</small></p></div>{{end}}
   </div>
   <div class="software-version-action">
-    {{if and .SoftwareUpdate.UpdateAvailable .SoftwareUpdate.AgentCompatible}}
+    {{if and .SoftwareUpdate.UpdateAvailable (not .SoftwareUpdate.ComposeSyncRequired)}}
     <form action="/system/update" method="post" data-software-update-form>
       <input type="hidden" name="csrf" value="{{.CSRF}}"><input type="hidden" name="version" value="{{.SoftwareUpdate.LatestVersion}}">
       <button class="button button-primary software-update-button" type="submit"><span>Jetzt aktualisieren</span><i aria-hidden="true">↗</i></button>
@@ -33,6 +33,15 @@
   </div>
 </section>
 
+<section class="panel container-restart-panel">
+  <span class="container-restart-icon" aria-hidden="true">↻</span>
+  <div class="container-restart-copy"><span class="section-label">Containersteuerung</span><h2>Anwendungscontainer neu starten</h2><p>Beendet den vollständigen DynDNS-Container geordnet und startet ihn mit unveränderten Daten, Secrets und Einstellungen neu. Der Dienst ist dabei kurz nicht erreichbar.</p></div>
+  <form action="/system/restart" method="post" data-container-restart-form data-instance-id="{{.InstanceID}}">
+    <input type="hidden" name="csrf" value="{{.CSRF}}">
+    <button class="button button-quiet" type="submit">Container neu starten</button>
+  </form>
+</section>
+
 <section class="panel update-credential-panel {{if .SoftwareUpdate.CredentialConfigured}}is-connected{{end}}" id="update-access">
   {{if .SoftwareUpdate.CredentialConfigured}}
   <div class="update-access-state">
@@ -54,5 +63,19 @@
   {{if .SoftwareUpdate.CredentialConfigured}}</details>{{end}}
 </section>
 
+<div class="software-update-overlay container-restart-overlay" data-container-restart-overlay data-update-state="restarting" hidden role="dialog" aria-modal="true" aria-labelledby="container-restart-title">
+  <div class="software-update-dialog">
+    <div class="software-update-visual" aria-hidden="true">
+      <span class="software-update-scan"></span>
+      <div class="software-update-orbit"><span>DC</span><i></i></div>
+    </div>
+    <span class="section-label">Container-Neustart</span>
+    <h2 id="container-restart-title" data-container-restart-title>Neustart wird vorbereitet</h2>
+    <p data-container-restart-message aria-live="polite">Die Anwendung wird geordnet beendet und automatisch wieder gestartet.</p>
+    <div class="container-restart-progress" aria-hidden="true"><i></i></div>
+    <button class="button button-quiet" type="button" data-container-restart-close hidden>Schließen</button>
+  </div>
+</div>
+
 {{template "software_update_overlay" .}}
 {{end}}