Refactor Chinese Mainland location handling

Moved 'Chinese Mainland 🇨🇳' from a dedicated proxy group to the general locations array. Updated proxy group definitions to use the unified locations list, simplifying configuration and reducing redundancy.

META.js

@@ -49,6 +49,12 @@ const services = [
 const LOCATION_ICON_SET_URL = "https://img.icons8.com/color/144/";
 
 const locations = [
+  {
+    name: "Chinese Mainland 🇨🇳",
+    icon: `${LOCATION_ICON_SET_URL}china`,
+    filter:
+      "(?i)\u5927\u9646|\u4e2d\u56fd|\u7535\u4fe1|\u79fb\u52a8|\u8054\u901a|Mainland|China|CN|mainland|china|cn|🇨🇳",
+  },
   {
     name: "Argentina 🇦🇷",
     icon: `${LOCATION_ICON_SET_URL}argentina`,
@@ -266,7 +272,6 @@ const serviceProxyGroupProxies = [
   ...staticProxyNames,
   "AUTO",
   "DIRECT",
-  "Chinese Mainland 🇨🇳",
   ...locations.map(({ name }) => name),
 ];
 
@@ -385,7 +390,6 @@ const proxyGroups = [
     proxies: [
       ...staticProxyNames,
       "AUTO",
-      "Chinese Mainland 🇨🇳",
       ...locations.map(({ name }) => name),
     ],
     icon: `${BASE_ICON_SET_URL}Proxy.png`,
@@ -406,11 +410,11 @@ const proxyGroups = [
     name: "Domestic",
     type: "select",
     proxies: [
-      "Chinese Mainland 🇨🇳",
+      "DIRECT",
+      ...locations.map(({ name }) => name),
       "PROXY",
       ...staticProxyNames,
       "AUTO",
-      ...locations.map(({ name }) => name),
     ],
     icon: `${BASE_ICON_SET_URL}Domestic.png`,
   },
@@ -428,16 +432,6 @@ const proxyGroups = [
     proxies: ["REJECT", "DIRECT", ...staticProxyNames],
     icon: `${BASE_ICON_SET_URL}Advertising.png`,
   },
-  {
-    ...locationPolicyProxyGroupDefaults,
-    name: "Chinese Mainland 🇨🇳",
-    type: "select",
-    icon: `${LOCATION_ICON_SET_URL}china`,
-    proxies: ["DIRECT"],
-    "include-all": true,
-    filter:
-      "(?i)\u5927\u9646|\u4e2d\u56fd|\u7535\u4fe1|\u79fb\u52a8|\u8054\u901a|Mainland|China|CN|mainland|china|cn|🇨🇳",
-  },
   ...generateLocationPolicyProxyGroups(
     locations,
     locationPolicyProxyGroupDefaults,