Enhance DeviceContext to fetch and manage PEQ state; update EQPage to synchronize PEQ catalog and improve headphone selection logic based on PEQ state changes. Refactor related functions for better state handling and synchronization.

client/src/contexts/DeviceContext.tsx

@@ -67,6 +67,11 @@ export function DeviceProvider({ children }: { children: React.ReactNode }) {
     lastMsgCountRef.current = state.msgCount;
   }, []);
 
+  const fetchPeqState = useCallback(async (apiInstance: LuxsinAPI) => {
+    const peq = await apiInstance.getPeqState();
+    setPeqState(peq);
+  }, []);
+
   const connect = useCallback(async (forceDemo?: boolean, connectIp?: string) => {
     const useDemo = forceDemo !== undefined ? forceDemo : isDemoMode;
     const targetIp = (connectIp ?? ip).trim();
@@ -138,10 +143,11 @@ export function DeviceProvider({ children }: { children: React.ReactNode }) {
     if (!apiInstance) return;
     try {
       await fetchState(apiInstance);
+      await fetchPeqState(apiInstance).catch(() => undefined);
     } catch (e) {
       setError(`Refresh failed: ${e instanceof Error ? e.message : String(e)}`);
     }
-  }, [api, isConnected, ip, isDemoMode, fetchState]);
+  }, [api, isConnected, ip, isDemoMode, fetchState, fetchPeqState]);
 
   const updateSetting = useCallback(async (params: Record<string, string | number>) => {
     if (isDemoMode) {
@@ -235,7 +241,10 @@ export function DeviceProvider({ children }: { children: React.ReactNode }) {
       try {
         const count = await api.getMsgCount();
         if (count !== lastMsgCountRef.current) {
-          await fetchState(api);
+          await Promise.all([
+            fetchState(api),
+            fetchPeqState(api).catch(() => undefined),
+          ]);
         }
       } catch {
         // Silently fail polling
@@ -246,7 +255,7 @@ export function DeviceProvider({ children }: { children: React.ReactNode }) {
     return () => {
       if (pollIntervalRef.current) clearInterval(pollIntervalRef.current);
     };
-  }, [isConnected, isDemoMode, api, fetchState]);
+  }, [isConnected, isDemoMode, api, fetchState, fetchPeqState]);
 
   return (
     <DeviceContext.Provider value={{