fix: hide used_by when only one source is present

used_by (share names) shown only when path has both samba and nfs
to avoid redundancy with the source chips.

web/src/pages/Dashboard.tsx

@@ -50,7 +50,7 @@ export default function Dashboard() {
                           {SOURCE_LABELS[s] ?? s}
                         </span>
                       ))}
-                      {d.used_by && d.used_by.length > 0 && (
+                      {d.used_by && d.used_by.length > 0 && d.sources.length > 1 && (
                         <span className="text-xs text-slate-500">{d.used_by.join(", ")}</span>
                       )}
                     </div>

web/src/pages/Settings.tsx

@@ -31,7 +31,7 @@ function DiskUsageItem({ disk }: { disk: SystemStatus["disks"][number] }) {
               {SOURCE_LABELS[s] ?? s}
             </span>
           ))}
-          {disk.used_by && disk.used_by.length > 0 && (
+          {disk.used_by && disk.used_by.length > 0 && disk.sources.length > 1 && (
             <div className="flex flex-wrap gap-1">
               {disk.used_by.map((name) => (
                 <span key={name} className="rounded bg-slate-700 px-1.5 py-0.5 text-xs text-slate-300">