fix: report billing counts only sent/paid invoices as Invoiced

Draft invoices and orphaned invoice line items (invoice deleted → null)
no longer count as Invoiced on the billing report, matching what the
Finances page shows as issued. Not-invoiced/invoiced/paid buckets still
sum to total version rows. No-op on current data (no drafts/orphans);
guards future drafts.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/pages/team/TeamReports.jsx

@@ -15,8 +15,12 @@ function fmtVersion(versionNumber) {
 }
 
 function billingStatusFromInvoices(items = []) {
-  if (!items.length) return 'not_started';
-  if (items.some((item) => item.invoice?.status === 'paid')) return 'paid';
+  // Only a sent or paid invoice counts as billed. Draft invoices and orphaned
+  // line items (invoice deleted → invoice null) are treated as Not Invoiced,
+  // matching what the Finances page actually shows as issued.
+  const issued = items.filter((item) => item.invoice?.status === 'sent' || item.invoice?.status === 'paid');
+  if (!issued.length) return 'not_started';
+  if (issued.some((item) => item.invoice?.status === 'paid')) return 'paid';
   return 'invoiced';
 }