[fix](trx-frontend-http): drop the rig description from the top bar

The header repeated the active rig's hardware string and mode list beside
the rig picker.  With a real SDR that reads

  SoapySDR driver=airspyhf,serial=c852eb5dd23539f8 · RX · SDR filters ·
  LSB · USB · CW · CWR · AM · +7 modes

which is longer than every other control in the bar combined, and it is
already on the About tab in full, split across its Rig, Active rig,
Connection, Modes and VFO rows.

Remove the element and the builder behind it.  Rig switching keeps its
feedback through the existing hint channel rather than by briefly
rewriting a permanent label, and the identity that belongs in a header —
the rig's display name — stays in the left subtitle.

The freed width is not spent: the tab strip now reaches Settings before
it needs to scroll, where it previously faded out during Statistics.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GdyUjuXejCEfiub675z6cz
Signed-off-by: Stan Grams <sjg@haxx.space>

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

@@ -1419,18 +1419,6 @@ small { color: var(--text-muted); }
   gap: 0.4rem;
   min-width: 0;
 }
-.header-rig-summary {
-  display: block;
-  max-width: 12rem;
-  flex: 0 1 auto;
-  min-width: 0;
-  color: var(--text-muted);
-  font-size: var(--fs-xs);
-  line-height: 1.35;
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
-}
 .header-rig-switch select {
   min-width: 8rem;
   height: 2rem;
@@ -3332,8 +3320,6 @@ body[data-operator-layout="broadcast"] #cw-bar-overlay {
     width: auto;
     min-width: 0;
   }
-  /* Rig hardware/feature detail is on the left subtitle and the About tab. */
-  .header-rig-summary { display: none; }
   .header-bar-btn {
     flex: 0 0 auto;
     min-width: 0;