feat: 支持列出显示器。

src/models/display-state.model.ts

@@ -0,0 +1,16 @@
+export type DisplayState = {
+  brightness: number;
+  max_brightness: number;
+  min_brightness: number;
+  contrast: number;
+  max_contrast: number;
+  min_contrast: number;
+  mode: number;
+  max_mode: number;
+  min_mode: number;
+  last_modified_at: Date;
+};
+
+export type RawDisplayState = DisplayState & {
+  last_modified_at: { secs_since_epoch: number };
+};