Scaffold monorepo: engine, server, and web packages

npm workspaces with three TypeScript packages: @wizwar/engine (pure
game logic), @wizwar/server (Node websocket authority), @wizwar/web
(Svelte 5 + Vite client). Server handshake and client build verified.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/web/src/App.svelte

@@ -0,0 +1,19 @@
+<script lang="ts">
+  let status = $state("disconnected");
+
+  const ws = new WebSocket("ws://localhost:8787");
+  ws.onopen = () => (status = "connected");
+  ws.onclose = () => (status = "disconnected");
+</script>
+
+<main>
+  <h1>Wiz-War</h1>
+  <p>server: {status}</p>
+</main>
+
+<style>
+  main {
+    font-family: system-ui, sans-serif;
+    padding: 2rem;
+  }
+</style>