refactor(proxy): enhance proxy state management and refresh logic

src-tauri/src/state/proxy.rs

@@ -1,6 +1,7 @@
 pub struct CmdProxyState {
     pub last_refresh_time: std::time::Instant,
     pub need_refresh: bool,
+    pub proxies: serde_json::Value,
     pub providers_proxies: serde_json::Value,
 }
 
@@ -9,6 +10,7 @@ impl Default for CmdProxyState {
         Self {
             last_refresh_time: std::time::Instant::now(),
             need_refresh: true,
+            proxies: serde_json::Value::Null,
             providers_proxies: serde_json::Value::Null,
         }
     }