feat: Sprint 0 — project scaffold, DB schema, Zustand stores, base UI components

store/useUserStore.ts

@@ -0,0 +1,19 @@
+import { create } from 'zustand';
+
+export interface User {
+  id: string;
+  displayName: string;
+  shareId: string;
+}
+
+interface UserStore {
+  user: User | null;
+  setUser: (user: User) => void;
+  clearUser: () => void;
+}
+
+export const useUserStore = create<UserStore>((set) => ({
+  user: null,
+  setUser: (user) => set({ user }),
+  clearUser: () => set({ user: null }),
+}));