[style](trx-frontend-http): tighten APRS bar entry spacing

Remove inter-frame gap and reduce line-height 1.45→1.2.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css

@@ -643,7 +643,7 @@ small { color: var(--text-muted); }
   max-height: 60%;
   overflow-y: auto;
   flex-direction: column;
-  gap: 0.1rem;
+  gap: 0;
 }
 .aprs-bar-header {
   display: flex;
@@ -680,7 +680,7 @@ small { color: var(--text-muted); }
 .aprs-bar-frame {
   font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
   font-size: clamp(0.58rem, 1.05vw, 0.74rem);
-  line-height: 1.45;
+  line-height: 1.2;
   opacity: 1;
 }
 .aprs-bar-frame-main {