feat: remove state and let rust handle

src/types.ts

@@ -1,4 +1,4 @@
-import { DSPState as DSP408State, Meters as DSP408Meters } from './features/dsp408/types';
+import { DSPState as DSP408State, Meters as DSP408Meters, DSPMode } from './features/dsp408/types';
 
 export type DSPStatus = 'connected' | 'connecting' | 'disconnected';
 
@@ -31,7 +31,7 @@ interface DSPBase {
   ip: string;
   port: number;
   deviceId: number;
-  demo: boolean;
+  mode: DSPMode;
 
   status: DSPStatus;