fix(awards): hide Missing refs where it cannot mean anything

"In this award's scope but with no reference" needs a scope to be in. On a
worldwide reference award — POTA, SOTA, IOTA, WWFF — every contact anywhere
would qualify, so the backend returns nothing and the window says it found
nothing. The button was there regardless, and could only ever open that.

It now appears only for an award scoped to a DXCC entity, which is what the
help text underneath used to have to explain. Better than what I did first,
which was to make a useless screen fast.

Kept from that: the assign dropdown is searched rather than scrolled above 300
references, and the reference list is not fetched until there are rows to
assign it to. Both still bite on a scoped award with a long list — Russian
districts, the bigger European ones.

frontend/src/components/AwardsPanel.tsx

@@ -64,7 +64,9 @@ function ProgressBar({ worked, confirmed, total }: { worked: number; confirmed:
   );
 }
 
-type AwardListItem = { code: string; name: string; valid?: boolean; bands?: string[]; emission?: string[] };
+// scoped: the award is limited to one or more DXCC entities. Missing-reference
+// detection only means anything for those — see the Missing refs button.
+type AwardListItem = { code: string; name: string; valid?: boolean; bands?: string[]; emission?: string[]; scoped?: boolean };
 
 export function AwardsPanel({ onEditQSO, onAwardsChanged }: { onEditQSO?: (id: number) => void; onAwardsChanged?: () => void } = {}) {
   const { t } = useI18n();
@@ -150,7 +152,7 @@ export function AwardsPanel({ onEditQSO, onAwardsChanged }: { onEditQSO?: (id: n
       ]);
       const follow = new Set(tracked);
       let list: AwardListItem[] = defs
-        .map((d) => ({ code: d.code, name: d.name, valid: d.valid, bands: d.valid_bands ?? [], emission: d.emission ?? [] }))
+        .map((d) => ({ code: d.code, name: d.name, valid: d.valid, bands: d.valid_bands ?? [], emission: d.emission ?? [], scoped: (d.dxcc_filter ?? []).length > 0 }))
         .sort((a, b) => a.code.localeCompare(b.code));
       if (follow.size > 0) list = list.filter((a) => follow.has(a.code));
       setAwardList(list);
@@ -427,13 +429,21 @@ export function AwardsPanel({ onEditQSO, onAwardsChanged }: { onEditQSO?: (id: n
                 ))}
               </div>
               <span className="text-xs text-muted-foreground">{filteredRefs.length} {t('awp.refs')}</span>
-              <button
-                onClick={() => setShowMissing(true)}
-                className="flex items-center gap-1 text-xs text-warning-muted-foreground hover:text-warning border border-warning-border bg-warning-muted rounded px-2 py-1"
-                title={t('awp.missingRefsTitle')}
-              >
-                <AlertTriangle className="size-3" /> {t('awp.missingRefs')}
-              </button>
+              {/* Only for an award scoped to a DXCC entity. "In this award's
+                  scope but with no reference" needs a scope to be in: on a
+                  worldwide reference award — POTA, SOTA, IOTA, WWFF — every
+                  contact anywhere would qualify, so the answer is always none.
+                  The button used to be there regardless and could only ever
+                  open a window saying it had found nothing. */}
+              {awardList.find((a) => a.code === selected)?.scoped && (
+                <button
+                  onClick={() => setShowMissing(true)}
+                  className="flex items-center gap-1 text-xs text-warning-muted-foreground hover:text-warning border border-warning-border bg-warning-muted rounded px-2 py-1"
+                  title={t('awp.missingRefsTitle')}
+                >
+                  <AlertTriangle className="size-3" /> {t('awp.missingRefs')}
+                </button>
+              )}
               <div className="flex-1" />
               {/* Legend */}
               <div className="flex items-center gap-2 text-[10px] text-muted-foreground">