Fix frontend API: use relative /api with Vite proxy to agent

frontend/src/lib/api.ts

@@ -1,6 +1,6 @@
 import type { NetObject, ServiceInfo } from '../types';
 
-const AGENT_BASE = 'http://127.0.0.1:8001';
+const AGENT_BASE = '/api';
 
 export async function fetchObjects(): Promise<NetObject[]> {
   return [

frontend/vite.config.ts

@@ -0,0 +1,16 @@
+import { defineConfig } from 'vite';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    host: '0.0.0.0',
+    port: 5173,
+    proxy: {
+      '/api': {
+        target: 'http://127.0.0.1:8001',
+        changeOrigin: true,
+      },
+    },
+  },
+});