feat: implement frontend login functionality with form handling and error management

apps/frontend/app/components/home/TablePlaceholder.tsx

@@ -0,0 +1,27 @@
+import React from 'react';
+import { Flex, Text, Button, Separator, Box, Badge } from '@radix-ui/themes';
+
+export default function TablePlaceholder() {
+  return (
+    <Flex direction="column" gap="3" p="4">
+      <Flex justify="between" align="center">
+        <Text weight="bold">Proxy Hosts</Text>
+        <Button size="1">Add Host</Button>
+      </Flex>
+      <Separator size="4" />
+      {[1, 2, 3].map((i) => (
+        <Flex key={i} justify="between" align="center">
+          <Box>
+            <Text size="2" weight="bold" as="div">
+              {`host-${i}.example.com`}
+            </Text>
+            <Text size="1" color="gray">
+              {`http://10.0.0.${i}:8080`}
+            </Text>
+          </Box>
+          <Badge color="green">Online</Badge>
+        </Flex>
+      ))}
+    </Flex>
+  );
+}