add viewMode store for grid/list toggle persistence

src/lib/stores/viewMode.svelte.ts

@@ -0,0 +1,63 @@
+export type ViewMode = 'grid' | 'list'
+
+const COLLECTION_VIEW_KEY = 'collection-view-mode'
+const MODAL_VIEW_KEY = 'modal-view-mode'
+
+class ViewModeStore {
+	#collectionView = $state<ViewMode>('grid')
+	#modalView = $state<ViewMode>('grid')
+	#initialized = false
+
+	constructor() {
+		// Load from localStorage on client-side init
+		if (typeof window !== 'undefined') {
+			this.#loadFromStorage()
+		}
+	}
+
+	#loadFromStorage() {
+		if (this.#initialized) return
+		this.#initialized = true
+
+		const storedCollection = localStorage.getItem(COLLECTION_VIEW_KEY)
+		if (storedCollection === 'grid' || storedCollection === 'list') {
+			this.#collectionView = storedCollection
+		}
+
+		const storedModal = localStorage.getItem(MODAL_VIEW_KEY)
+		if (storedModal === 'grid' || storedModal === 'list') {
+			this.#modalView = storedModal
+		}
+	}
+
+	get collectionView(): ViewMode {
+		// Ensure we load from storage on first access (handles SSR -> client hydration)
+		if (typeof window !== 'undefined' && !this.#initialized) {
+			this.#loadFromStorage()
+		}
+		return this.#collectionView
+	}
+
+	get modalView(): ViewMode {
+		if (typeof window !== 'undefined' && !this.#initialized) {
+			this.#loadFromStorage()
+		}
+		return this.#modalView
+	}
+
+	setCollectionView(mode: ViewMode) {
+		this.#collectionView = mode
+		if (typeof window !== 'undefined') {
+			localStorage.setItem(COLLECTION_VIEW_KEY, mode)
+		}
+	}
+
+	setModalView(mode: ViewMode) {
+		this.#modalView = mode
+		if (typeof window !== 'undefined') {
+			localStorage.setItem(MODAL_VIEW_KEY, mode)
+		}
+	}
+}
+
+export const viewMode = new ViewModeStore()