Split viewer and simulation into separate apps

apps/viewer/vite.config.ts

@@ -0,0 +1,18 @@
+import { defineConfig } from "vite";
+
+const root = new URL(".", import.meta.url).pathname;
+
+export default defineConfig({
+  root,
+  server: {
+    host: true,
+    port: 5174,
+    proxy: {
+      "/api": "http://127.0.0.1:5079",
+    },
+  },
+  build: {
+    outDir: "../../dist/viewer",
+    emptyOutDir: true,
+  },
+});