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/ShareDeleteButton.tsx

@@ -0,0 +1,57 @@
+import { ConfirmationForm } from '@/components/common/ConfirmationForm';
+import { useDeleteQuery, useMessages, useModified } from '@/components/hooks';
+import { Trash } from '@/components/icons';
+import { DialogButton } from '@/components/input/DialogButton';
+import { messages } from '@/components/messages';
+
+export function ShareDeleteButton({
+  shareId,
+  slug,
+  onSave,
+}: {
+  shareId: string;
+  slug: string;
+  onSave?: () => void;
+}) {
+  const { formatMessage, labels, getErrorMessage, FormattedMessage } = useMessages();
+  const { mutateAsync, isPending, error } = useDeleteQuery(`/share/id/${shareId}`);
+  const { touch } = useModified();
+
+  const handleConfirm = async (close: () => void) => {
+    await mutateAsync(null, {
+      onSuccess: () => {
+        touch('shares');
+        onSave?.();
+        close();
+      },
+    });
+  };
+
+  return (
+    <DialogButton
+      icon={<Trash />}
+      title={formatMessage(labels.confirm)}
+      variant="quiet"
+      width="400px"
+    >
+      {({ close }) => (
+        <ConfirmationForm
+          message={
+            <FormattedMessage
+              {...messages.confirmRemove}
+              values={{
+                target: <b>{slug}</b>,
+              }}
+            />
+          }
+          isLoading={isPending}
+          error={getErrorMessage(error)}
+          onConfirm={handleConfirm.bind(null, close)}
+          onClose={close}
+          buttonLabel={formatMessage(labels.delete)}
+          buttonVariant="danger"
+        />
+      )}
+    </DialogButton>
+  );
+}