add clash api back, remove it won't resolve the port issue of running two instance, one in knox, one out

singbox.json

@@ -737,6 +737,13 @@
   "experimental": {
     "cache_file": {
       "enabled": true
+    },
+    "clash_api": {
+      "external_controller": "0.0.0.0:9090",
+      "external_ui": "metacubexd",
+      "external_ui_download_url": "https://github.com/MetaCubeX/metacubexd/archive/refs/heads/gh-pages.zip",
+      "external_ui_download_detour": "🚀 节点选择",
+      "default_mode": "rule"
     }
   }
 }