Add "truly done" ticket archiving with auto-unhide

- Let the user mark closed tickets as really done and hide them, so
  tickets closed prematurely by an agent stay visible until confirmed
- User-side "archived" flag stored in the DB (independent of Zammad),
  added via a schema migration on existing databases
- Hide archived tickets from the overview by default with an
  "erledigte einblenden" toggle; archive/unarchive from the ticket
  detail page and via a per-row quick action
- Poller automatically un-hides an archived ticket when new activity is
  detected, so nothing is missed

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

templates/index.html

@@ -46,22 +46,30 @@
 
   <section class="panel">
     <div class="panel-head"><h2>Status-Filter</h2></div>
+    {% set arch = '1' if show_archived else none %}
     <div class="chips">
-      <a class="chip {{ 'on' if not active_state }}" href="{{ url_for('index', sort=sort, dir=dir) }}">alle</a>
+      <a class="chip {{ 'on' if not active_state }}" href="{{ url_for('index', sort=sort, dir=dir, archived=arch) }}">alle</a>
       <a class="chip {{ 'on' if active_state == 'not_closed' }}"
-         href="{{ url_for('index', state='not_closed', sort=sort, dir=dir) }}">nicht geschlossen</a>
+         href="{{ url_for('index', state='not_closed', sort=sort, dir=dir, archived=arch) }}">nicht geschlossen</a>
       {% for s in states %}
         <a class="chip {{ 'on' if active_state == s.state }}"
-           href="{{ url_for('index', state=s.state, sort=sort, dir=dir) }}">{{ s.state }} ({{ s.c }})</a>
+           href="{{ url_for('index', state=s.state, sort=sort, dir=dir, archived=arch) }}">{{ s.state }} ({{ s.c }})</a>
       {% endfor %}
     </div>
+    <div class="chips" style="margin-top:.5rem">
+      {% if show_archived %}
+        <a class="chip on" href="{{ url_for('index', state=active_state or none, sort=sort, dir=dir) }}">erledigte ausblenden</a>
+      {% else %}
+        <a class="chip" href="{{ url_for('index', state=active_state or none, sort=sort, dir=dir, archived='1') }}">erledigte einblenden{% if archived_count %} ({{ archived_count }}){% endif %}</a>
+      {% endif %}
+    </div>
   </section>
 </div>
 
 {% macro th(col, label) %}
   {% set nextdir = 'asc' if (sort == col and dir == 'desc') else 'desc' %}
   <th class="{{ 'sorted' if sort == col }}">
-    <a href="{{ url_for('index', state=active_state or none, sort=col, dir=nextdir) }}">
+    <a href="{{ url_for('index', state=active_state or none, sort=col, dir=nextdir, archived=request.args.get('archived')) }}">
       {{ label }}{% if sort == col %} <span class="arrow">{{ '▼' if dir == 'desc' else '▲' }}</span>{% endif %}
     </a>
   </th>
@@ -77,25 +85,37 @@
         {{ th('number', '#') }}{{ th('title', 'Titel') }}{{ th('state', 'Status') }}
         {{ th('priority', 'Priorität') }}{{ th('owner', 'Bearbeiter') }}
         {{ th('articles', 'Artikel') }}{{ th('updated', 'zuletzt geändert') }}
+        <th></th>
       </tr>
     </thead>
     <tbody>
       {% for t in tickets %}
         {% set n = unseen_map.get(t.id) %}
-        <tr class="{{ 'row-unseen' if n }}">
+        <tr class="{{ 'row-unseen' if n }}{{ ' row-archived' if t.archived }}">
           <td>
             {% if n %}<span class="badge" title="{{ n }} unbestätigte Änderung(en)">{{ n }}</span>{% endif %}
             <a href="{{ url_for('ticket_detail', ticket_id=t.id) }}">{{ t.number }}</a>
           </td>
-          <td class="title">{{ t.title }}</td>
+          <td class="title">{{ t.title }}{% if t.archived %} <span class="tag">erledigt</span>{% endif %}</td>
           <td><span class="state state-{{ t.state }}">{{ t.state }}</span></td>
           <td>{{ t.priority }}</td>
           <td>{{ t.owner if t.owner and t.owner != '-' else '—' }}</td>
           <td>{{ t.article_count }}</td>
           <td><time>{{ t.zammad_updated_at|dt }}</time></td>
+          <td class="rowact">
+            {% if t.archived %}
+              <form method="post" action="{{ url_for('unarchive_ticket', ticket_id=t.id) }}">
+                <button type="submit" title="Wieder einblenden">↩</button>
+              </form>
+            {% else %}
+              <form method="post" action="{{ url_for('archive_ticket', ticket_id=t.id) }}">
+                <button type="submit" title="Als wirklich erledigt ablegen (ausblenden)">✓</button>
+              </form>
+            {% endif %}
+          </td>
         </tr>
       {% else %}
-        <tr><td colspan="7" class="muted">Keine Tickets.</td></tr>
+        <tr><td colspan="8" class="muted">Keine Tickets.</td></tr>
       {% endfor %}
     </tbody>
   </table>