fix(invoices): real empty states in the editor pickers (#1678)

Zero customers rendered the customer Select as a bare few-pixel sliver;
it now shows 'Inga kunder än'. The supplier menu showed an orphan
separator above its create action when no suppliers exist; it now shows
'Inga leverantörer än' and drops the separator. The row-entry suggestion
hint loses its top border when no article list renders above it.

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

components/invoices/InvoiceEditor.tsx

@@ -1960,6 +1960,13 @@ export default function InvoiceEditor(props: InvoiceEditorProps = { mode: 'creat
                     <SelectValue placeholder={t('select_customer_placeholder')} />
                   </SelectTrigger>
                   <SelectContent>
+                    {/* Radix renders an empty viewport as a bare few-pixel
+                        sliver; give the zero-customer state real content. */}
+                    {customers.length === 0 && (
+                      <div className="px-3 py-2 text-[13px] text-muted-foreground">
+                        {t('no_customers_yet')}
+                      </div>
+                    )}
                     {customers.map((customer) => (
                       <SelectItem key={customer.id} value={customer.id}>
                         {customer.name}
@@ -2608,7 +2615,12 @@ export default function InvoiceEditor(props: InvoiceEditorProps = { mode: 'creat
                   </div>
                   <div
                     id={`${entryListId}-hint`}
-                    className="border-t border-border px-3 py-2 text-[11px] text-muted-foreground"
+                    className={cn(
+                      'px-3 py-2 text-[11px] text-muted-foreground',
+                      // Border only when a list renders above; alone it reads
+                      // as a stray hairline at the top of the popover.
+                      entryMatches.length > 0 && 'border-t border-border',
+                    )}
                   >
                     {entryMatches.length > 0 ? t('entry_hint_matches') : t('entry_hint_free')}
                   </div>

components/supplier-invoices/NewSupplierInvoiceForm.tsx

@@ -1677,6 +1677,11 @@ export default function NewSupplierInvoiceForm({
                   e.preventDefault()
                 }}
               >
+                {suppliers.length === 0 && (
+                  <div className="px-2 py-2 text-[13px] text-muted-foreground">
+                    {t('no_suppliers_yet')}
+                  </div>
+                )}
                 {suppliers.map((s) => (
                   <DropdownMenuItem
                     key={s.id}
@@ -1695,7 +1700,8 @@ export default function NewSupplierInvoiceForm({
                     </div>
                   </DropdownMenuItem>
                 ))}
-                <DropdownMenuSeparator />
+                {/* No separator over an empty list: it reads as a stray line. */}
+                {suppliers.length > 0 && <DropdownMenuSeparator />}
                 <DropdownMenuItem onSelect={openSupplierDialogBlank} className="text-muted-foreground">
                   {t('add_new_supplier')}
                 </DropdownMenuItem>