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/_imaging_tiles.html

@@ -164,8 +164,8 @@
       {% endif %}
 
       <div class="mt-2 d-flex flex-wrap gap-3" style="color:var(--text-light); font-size:0.75rem;">
-        <span>started <code class="mono">{{ s.started_at or '-' }}</code></span>
-        <span>last <code class="mono">{{ s.last_updated or '-' }}</code></span>
+        <span>started <code class="mono">{{ s.started_at | local_dt(true) }}</code></span>
+        <span>last <code class="mono">{{ s.last_updated | local_dt(true) }}</code></span>
         <span>MAC <code class="mono">{{ s.mac or '-' }}</code></span>
         {% if s.current_stage %}<span class="mono">{{ s.current_stage }}</span>{% endif %}
       </div>