feat: listings view with useListings hook and table

app/src/hooks/useListings.ts

@@ -0,0 +1,17 @@
+import { useQuery } from '@tanstack/react-query'
+import { useCluster } from '@solana/connector/react'
+import { createSolanaRpc } from '@solana/kit'
+import { fetchAllListings } from '@solisting/sdk'
+
+export function useListings() {
+  const { cluster } = useCluster()
+  return useQuery({
+    queryKey: ['listings', cluster?.id],
+    queryFn: () => {
+      const rpc = createSolanaRpc(cluster!.url)
+      return fetchAllListings(rpc)
+    },
+    enabled: !!cluster,
+    refetchInterval: 30_000,
+  })
+}