Add embedded Express admin API and unified dev workflow.

Move admin backend into this repo (Express + MySQL on :8085) so npm run dev starts both API and Vite, with updated env defaults and Caddy config for gadm.tkmind.cn.

Co-authored-by: Cursor <cursoragent@cursor.com>

vite.config.ts

@@ -3,7 +3,7 @@ import react from '@vitejs/plugin-react';
 
 export default defineConfig(({ mode }) => {
   const env = loadEnv(mode, process.cwd(), '');
-  const backendTarget = env.ADM_DEV_BACKEND ?? 'http://127.0.0.1:8081';
+  const backendTarget = env.ADM_DEV_BACKEND ?? 'http://127.0.0.1:8085';
 
   return {
     plugins: [react()],
@@ -11,6 +11,7 @@ export default defineConfig(({ mode }) => {
       host: true,
       port: 5174,
       strictPort: true,
+      allowedHosts: ['gadm.tkmind.cn', 'localhost', '127.0.0.1'],
       proxy: {
         '/api': backendTarget,
         '/auth': backendTarget,
@@ -21,6 +22,7 @@ export default defineConfig(({ mode }) => {
       host: '127.0.0.1',
       port: 5174,
       strictPort: true,
+      allowedHosts: ['gadm.tkmind.cn', 'localhost', '127.0.0.1'],
       proxy: {
         '/api': backendTarget,
         '/auth': backendTarget,