feat: initialize project with Symfony, React, and Tailwind CSS setup

- Add package.json with development and production dependencies
- Create postcss.config.js for Tailwind CSS integration
- Implement AdminController for handling admin routes
- Add admin index template with React root element
- Create base template for consistent layout
- Configure TypeScript with tsconfig.json
- Set up Webpack configuration for asset management

assets/admin/stores/uiStore.ts

@@ -0,0 +1,13 @@
+import { create } from 'zustand';
+
+interface UiState {
+  sidebarOpen: boolean;
+  toggleSidebar: () => void;
+  setSidebarOpen: (open: boolean) => void;
+}
+
+export const useUiStore = create<UiState>((set) => ({
+  sidebarOpen: true,
+  toggleSidebar: () => set((s) => ({ sidebarOpen: !s.sidebarOpen })),
+  setSidebarOpen: (open) => set({ sidebarOpen: open }),
+}));