add volume storage in zustand

src/stores/volume/index.ts

@@ -0,0 +1,31 @@
+import { StateCreator, create } from "zustand";
+import { persist } from "zustand/middleware";
+import { immer } from "zustand/middleware/immer";
+
+export interface VolumeStore {
+  volume: number;
+  setVolume(v: number): void;
+}
+
+export type VolumeState = StateCreator<
+  VolumeStore,
+  [["zustand/persist", never]],
+  []
+>;
+
+// TODO add migration from previous stored volume
+export const useVolumeStore: VolumeState = create(
+  persist(
+    immer<VolumeStore>((set) => ({
+      volume: 1,
+      setVolume(v: number) {
+        set((s) => {
+          s.volume = v;
+        });
+      },
+    })),
+    {
+      name: "__MW::volume",
+    }
+  )
+);