Fix All Referrers chart showing numeric indices instead of source names

categories belong under xaxis in ApexCharts (even for horizontal bars); they
were under yaxis, so Apex fell back to numeric category indices. Moved them to
xaxis.categories — left axis now labels each bar with its referrer domain.

.github/scripts/accumulate-traffic.py

@@ -392,8 +392,8 @@ new ApexCharts(document.getElementById('allRefsChart'), {
   series:[{name:'Peak 14-day views',data:allRefs.map(([,d])=>d.count)},{name:'Unique',data:allRefs.map(([,d])=>d.uniques)}],
   colors:['#6366f1','#f59e0b'],
   plotOptions:{bar:{horizontal:true,borderRadius:4,barHeight:'65%',dataLabels:{position:'top'}}},
-  xaxis:{labels:{formatter:v=>v>=1000?(v/1000).toFixed(0)+'k':v}},
-  yaxis:{labels:{style:{fontSize:'11px'}},categories:allRefs.map(([n])=>n)},
+  xaxis:{categories:allRefs.map(([n])=>n),labels:{formatter:v=>v>=1000?(v/1000).toFixed(0)+'k':v}},
+  yaxis:{labels:{style:{fontSize:'11px'}}},
   dataLabels:{enabled:false},
   tooltip:{y:{formatter:v=>fmt(v)}},
   legend:{position:'top',horizontalAlign:'left',fontSize:'12px'},