build: assets link error

web/.env.production

@@ -1,2 +1,2 @@
 VITE_APP_API_URL=
-VITE_APP_BASE_PATH=/ui
+VITE_APP_BASE_PATH=/ui

web/vite.config.ts

@@ -2,25 +2,29 @@ import { reactRouter } from "@react-router/dev/vite";
 import tailwindcss from "@tailwindcss/vite";
 import mdx from "fumadocs-mdx/vite";
 import path from "node:path";
-import { env } from "node:process";
-import { defineConfig } from "vite";
+import { defineConfig, loadEnv } from "vite";
 import devtoolsJson from "vite-plugin-devtools-json";
 
 import * as MdxConfig from "./source.config";
 
-const isDev = env.NODE_ENV === "development";
-export default defineConfig({
-  base: isDev ? "/" : `${env.VITE_APP_API_URL}/`,
-  plugins: [mdx(MdxConfig), tailwindcss(), reactRouter(), devtoolsJson()],
-  resolve: {
-    tsconfigPaths: true,
-    alias: {
-      "@": path.resolve(__dirname, "./app"),
-      ...(!isDev
-        ? {
-            "react-dom/server": "react-dom/server.node",
-          }
-        : {}),
+export default defineConfig(({ command, mode }) => {
+  const env = loadEnv(mode, process.cwd(), "VITE_APP_");
+  const isDev = command === "serve";
+  const contextPath = env.VITE_APP_API_URL?.trim() ?? "";
+
+  return {
+    base: isDev || !contextPath ? "/" : `${contextPath}/`,
+    plugins: [mdx(MdxConfig), tailwindcss(), reactRouter(), devtoolsJson()],
+    resolve: {
+      tsconfigPaths: true,
+      alias: {
+        "@": path.resolve(__dirname, "./app"),
+        ...(!isDev
+          ? {
+              "react-dom/server": "react-dom/server.node",
+            }
+          : {}),
+      },
     },
-  },
+  };
 });