implement website share functionality using share table

- Add support for multiple share URLs per website with server-generated slugs
- Create shares API endpoint for listing and creating website shares
- Add SharesTable, ShareEditButton, ShareDeleteButton components
- Move share management to website settings, remove header share button
- Remove shareId from website update API (now uses separate share table)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/(main)/websites/[websiteId]/settings/ShareEditButton.tsx

@@ -0,0 +1,16 @@
+import { useMessages } from '@/components/hooks';
+import { Edit } from '@/components/icons';
+import { DialogButton } from '@/components/input/DialogButton';
+import { ShareEditForm } from './ShareEditForm';
+
+export function ShareEditButton({ shareId }: { shareId: string }) {
+  const { formatMessage, labels } = useMessages();
+
+  return (
+    <DialogButton icon={<Edit />} title={formatMessage(labels.share)} variant="quiet" width="600px">
+      {({ close }) => {
+        return <ShareEditForm shareId={shareId} onClose={close} />;
+      }}
+    </DialogButton>
+  );
+}