Report disk capacity in decimal GB so it matches Unraid and the drive label

The API mixes units per field — memory in bytes, disk size in KiB, fsSize and
fsUsed in kB — and one helper was guessing which from the magnitude of the
number, which also read any memory total under 100 GB as KB.

Plugin/unraid/pages/monitor.php

@@ -738,7 +738,9 @@ function vvTempColor(tempC, transport) {
   return tempC >= crit ? '#f44336' : tempC >= warn ? '#ff9800' : '#4caf50';
 }
 
-function vvFmt(v) { return v >= 1024 ? (v / 1024).toFixed(1) + ' TB' : v + ' GB'; }
+// Capacity only — size_gb/used_gb are decimal GB, so TB is 1000 of them. vvFmtGb below is the
+// binary one and stays binary: it formats cumulative bytes read/written, not drive capacity.
+function vvFmt(v) { return v >= 1000 ? (v / 1000).toFixed(1) + ' TB' : v + ' GB'; }
 
 function vvFmtRate(mbs) {
   if (mbs >= 1000) return (mbs / 1024).toFixed(1) + ' GB/s';