fix: Bandmap scroll bar to top

frontend/src/components/BandMap.tsx

@@ -284,6 +284,10 @@ export function BandMap({ band, spots, spotStatus, currentFreqHz, onSpotClick, o
       out.push({ spot: filtered[i], freqY: desired[i], labelY: centers[i] + shift - PILL_H / 2 });
     }
     const lastLabelBottom = out.length ? out[out.length - 1].labelY + PILL_H : 0;
+    // In fit mode the band scale exactly fills the viewport (innerH = containerH
+    // − pads); when crowded sub-bands stack labels past the bottom the content
+    // grows and a scroll bar appears — the map defaults to the top so the whole
+    // band is visible, and you scroll down to reach the stacked spots.
     return {
       placed: out,
       totalH: Math.max(innerH + TOP_PAD + BOT_PAD, lastLabelBottom + BOT_PAD),
@@ -300,15 +304,19 @@ export function BandMap({ band, spots, spotStatus, currentFreqHz, onSpotClick, o
   // frequency actually changes (or band/zoom/size), so tuning follows the rig
   // while a stable frequency leaves your manual scroll alone.
   useEffect(() => {
-    if (!range || containerH <= 0 || currentFreqHz <= 0) return;
-    const kHz = currentFreqHz / 1000;
-    if (kHz < lo || kHz > hi) return;
+    if (!range || containerH <= 0) return;
     const el = scrollerRef.current;
     if (!el) return;
+    // Fit-to-band: keep the view at the top so the full band is always in frame;
+    // any overflow spots are reached by scrolling down (don't follow the rig).
+    if (fitToBand) { el.scrollTop = 0; return; }
+    if (currentFreqHz <= 0) return;
+    const kHz = currentFreqHz / 1000;
+    if (kHz < lo || kHz > hi) return;
     el.scrollTop = Math.max(0, freqToY(kHz) - containerH / 2);
     // freqToY is recomputed each render; intentionally excluded from deps.
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [band, containerH, currentFreqHz, range, lo, hi, pxPerKHz]);
+  }, [band, containerH, currentFreqHz, range, lo, hi, pxPerKHz, fitToBand]);
 
   useEffect(() => {
     const el = scrollerRef.current;