feat: add embedded svelte frontend

ui/vite.config.ts

@@ -0,0 +1,31 @@
+import { defineConfig } from 'vite';
+import { svelte } from '@sveltejs/vite-plugin-svelte';
+import tailwindcss from '@tailwindcss/vite';
+
+const backendTarget = process.env.AMCS_UI_BACKEND ?? 'http://127.0.0.1:8080';
+
+export default defineConfig({
+  plugins: [svelte(), tailwindcss()],
+  server: {
+    host: '0.0.0.0',
+    port: 5173,
+    proxy: {
+      '/api': backendTarget,
+      '/healthz': backendTarget,
+      '/readyz': backendTarget,
+      '/llm': backendTarget,
+      '/images': backendTarget,
+      '/favicon.ico': backendTarget,
+      '/mcp': backendTarget,
+      '/files': backendTarget,
+      '/oauth-authorization-server': backendTarget,
+      '/authorize': backendTarget,
+      '/oauth': backendTarget,
+      '/.well-known': backendTarget
+    }
+  },
+  build: {
+    outDir: '../internal/app/ui/dist',
+    emptyOutDir: true
+  }
+});