fix(ui): one section name, a chosen digital row, no MQTT chip

Three things reported together.

Preferences said the section name twice: a small line above every panel
repeated the heading right underneath it — "GENERAL" over "General" —
while the sidebar next to them already shows which section is open,
highlighted. Two lines and a highlight for one fact; the small line goes.

The band matrix opens on the digital row the operator chooses. Its
digital row has always rotated — DIGI, then each digital mode in their
own list — but it always STARTED on DIGI, so somebody who only works FT8
clicked through to their own mode on every callsign. Settings ▸ General
now says where the rotation starts, and the dropdown offers exactly the
modes the matrix rotates through (the phone-mode rule is now shared
rather than copied, so the two cannot drift). DIGI stays the default: it
is the right answer for anyone working several digital modes.

And the MQTT chip is gone from the status bar. That is the name of a
message protocol, not of anything an operator has — a chip in the status
bar has to say what it is about, and this one told nobody anything. What
it carried is shown in the Chase New panel, which is the place that uses
it; its poller went with it.

frontend/src/components/BandSlotGrid.tsx

@@ -60,7 +60,11 @@ const DEFAULT_BANDS: { tag: string; label: string }[] = [
 ];
 const CLASSES = ['PH', 'CW', 'DIG'] as const;
 
-const PHONE_MODES = new Set(['SSB','USB','LSB','AM','FM','DIGITALVOICE','PHONE']);
+export const PHONE_MODES = new Set(['SSB','USB','LSB','AM','FM','DIGITALVOICE','PHONE']);
+
+// Which digital row the matrix opens on. Empty = DIG, the group of them all.
+// Set in Settings ▸ General; see the rotation below.
+export const MATRIX_DIGI_KEY = 'opslog.matrixDigiMode';
 function classMatchesMode(cls: string, mode: string): boolean {
   const u = (mode || '').toUpperCase();
   if (cls === 'PH') return PHONE_MODES.has(u);
@@ -143,7 +147,17 @@ export function BandSlotGrid({ wb, busy, currentBand, currentMode, bands, modes,
       .filter((m) => m !== '' && m !== 'CW' && !PHONE_MODES.has(m)),
     [modes],
   );
+  // Where the rotation STARTS. An operator who only ever works FT8 was shown
+  // "DIG" every time and had to click to the mode they actually use, on every
+  // callsign — so the row they want is the one it opens on. Empty (the default)
+  // keeps DIG, which is right for anyone working several digital modes.
   const [digIdx, setDigIdx] = useState(0); // 0 = the DIG group itself
+  useEffect(() => {
+    const want = (localStorage.getItem(MATRIX_DIGI_KEY) || '').toUpperCase().trim();
+    if (!want) { setDigIdx(0); return; }
+    const i = digModes.indexOf(want);
+    setDigIdx(i >= 0 ? i + 1 : 0);
+  }, [digModes]);
   // A shorter mode list (the operator edited it) must not strand the rotation
   // on a row that no longer exists.
   const digPos = digModes.length ? digIdx % (digModes.length + 1) : 0;