feat(ui): add Send/Re-send button on invoices page and order block

app/routes/app.invoices.tsx

@@ -234,13 +234,16 @@ function FilterChip({
 
 function OrderRow({ order }: { order: RecentOrder }) {
   const fetcher = useFetcher<{ ok: boolean; error?: string; invoiceNumber?: string }>();
+  const sendFetcher = useFetcher<{ ok: boolean; error?: string }>();
   const isBusy = fetcher.state !== "idle";
+  const isSending = sendFetcher.state !== "idle";
   const isCancelReissue = order.hasInvoice && order.invoiceSent;
   const buttonLabel = !order.hasInvoice
     ? "Generate"
     : order.invoiceSent
       ? "Cancel & reissue"
       : "Regenerate";
+  const sendLabel = order.invoiceSent ? "Re-send" : "Send";
 
   return (
     <s-table-row>
@@ -271,6 +274,9 @@ function OrderRow({ order }: { order: RecentOrder }) {
             {fetcher.data?.error ? (
               <s-text tone="critical">{fetcher.data.error}</s-text>
             ) : null}
+            {sendFetcher.data?.error ? (
+              <s-text tone="critical">{sendFetcher.data.error}</s-text>
+            ) : null}
           </s-stack>
         ) : (
           <s-text tone="neutral">—</s-text>
@@ -289,13 +295,23 @@ function OrderRow({ order }: { order: RecentOrder }) {
             ) : null}
             <s-button
               type="submit"
-              disabled={isBusy}
+              disabled={isBusy || isSending}
               variant={order.hasInvoice ? "secondary" : "primary"}
               tone={isCancelReissue ? "critical" : "auto"}
             >
               {isBusy ? "Working…" : buttonLabel}
             </s-button>
           </fetcher.Form>
+          <sendFetcher.Form method="post" action={`/api/orders/${order.numericId}/invoice`}>
+            <input type="hidden" name="action" value="send" />
+            <s-button
+              type="submit"
+              disabled={isBusy || isSending}
+              variant={order.hasInvoice && !order.invoiceSent ? "primary" : "secondary"}
+            >
+              {isSending ? "Sending…" : sendLabel}
+            </s-button>
+          </sendFetcher.Form>
         </s-stack>
       </s-table-cell>
     </s-table-row>