Show every time in US Eastern (America/New_York)

Webapp: config.DISPLAY_TZ (default America/New_York) and a local_dt
filter that renders datetimes, ISO strings and Unix timestamps as e.g.
"2026-10-05 13:54 EDT", DST included. Used for the ServiceNow tick list,
technician to-do, imaging tiles and detail page; timestamp_fmt (reports,
backups, enrollment) goes through it too instead of relying on the
process TZ. CSV report_date is Eastern with its offset. Evidence-pack
months are Eastern calendar months, so a wipe late on the 31st lands in
that month rather than the next.

Blancco: init points the new root's /etc/localtime at America/New_York
so the GUI clock is local. Report timestamps keep their explicit
offset; report.utc_offset stays 0 since a fixed offset cannot follow DST.
Report file names stay UTC, as Blancco's own Save names them.

webapp/templates/reports_servicenow.html

@@ -33,7 +33,7 @@
         <tr>
           <th>Serial</th>
           <th>Model</th>
-          <th>Wiped (UTC)</th>
+          <th>Wiped</th>
           <th>Tick in ServiceNow</th>
           <th>Destruction note</th>
           <th>Cloud</th>
@@ -48,7 +48,7 @@
             {% if it.serial %}<button type="button" class="btn btn-sm btn-outline-secondary btn-row-action copy-btn" data-copy-text="{{ it.serial }}">copy</button>{% endif %}
           </td>
           <td>{{ it.model or '-' }}</td>
-          <td class="mono text-nowrap">{{ it.when.strftime('%Y-%m-%d %H:%M') }}</td>
+          <td class="mono text-nowrap">{{ it.when | local_dt }}</td>
           <td>
             {% if it.failed %}<span class="badge badge-danger">Blancco Wipe failed</span>
             {% else %}<span class="badge badge-success">Wiped</span>{% endif %}