Left-align log-table headers to match their left-aligned data cells

Last Heard (and other log-style tables sharing this pattern) render
every <td> with align="left", but headers inherit the sitewide
table { text-align: center; } with nothing overriding it - so the
caption drifts toward the middle of wide columns (most visible on
Target) while the actual data underneath hugs the left edge. Looks
like a column-boundary misalignment at a glance, but it's a text-align
mismatch; measured actual cell boundaries and they line up exactly.

Scoped via a new .log-table class rather than changing table th
sitewide, since ~90% of the dashboard's other tables intentionally
keep centered cells (only 6-7 files use align="left" data cells).

mmdvmhost/lh.php

@@ -57,7 +57,7 @@ if ($callsignLookupSvc == "QRZ") { $callsignLookupUrl = "https://www.qrz.com/db/
 
 ?>
 <b><?php echo $lang['last_heard_list'];?></b>
-  <table>
+  <table class="log-table">
     <tr>
       <th><a class="tooltip" href="#"><?php echo $lang['time'];?> (<?php echo date('T')?>)<span><b>Time in <?php echo date('T')?> time zone</b></span></a></th>
       <th><a class="tooltip" href="#"><?php echo $lang['mode'];?><span><b>Transmitted Mode</b></span></a></th>