add separate checkboxes for variants

src/lib/checklist.ts

@@ -1,9 +1,15 @@
-export const CHECKLIST_KEY = 'magikarp-checklist-v1';
+export const CHECKLIST_KEY_V1 = 'magikarp-checklist-v1';
+export const CHECKLIST_KEY_V2 = 'magikarp-checklist-v2';
 
-export function loadChecklist(): Set<string> {
+export type VariantKey = 'base' | 'holofoil' | 'reverseHolofoil';
+export type VariantState = Partial<Record<VariantKey, boolean>>;
+export type ChecklistV2 = Record<string, VariantState>; // cardId -> variant flags
+
+// Legacy loader (v1)
+export function loadChecklistV1(): Set<string> {
   if (typeof window === 'undefined') return new Set();
   try {
-    const raw = localStorage.getItem(CHECKLIST_KEY);
+    const raw = localStorage.getItem(CHECKLIST_KEY_V1);
     if (!raw) return new Set();
     const arr = JSON.parse(raw) as string[];
     return new Set(arr);
@@ -12,10 +18,30 @@ export function loadChecklist(): Set<string> {
   }
 }
 
-export function saveChecklist(set: Set<string>) {
+// New storage (v2)
+export function loadChecklist(): ChecklistV2 {
+  if (typeof window === 'undefined') return {};
+  try {
+    const v2 = localStorage.getItem(CHECKLIST_KEY_V2);
+    if (v2) return JSON.parse(v2) as ChecklistV2;
+    // migrate from v1 if present
+    const v1 = loadChecklistV1();
+    if (v1.size === 0) return {};
+    const migrated: ChecklistV2 = {};
+    v1.forEach((id) => {
+      migrated[id] = { base: true };
+    });
+    saveChecklist(migrated);
+    return migrated;
+  } catch {
+    return {};
+  }
+}
+
+export function saveChecklist(state: ChecklistV2) {
   if (typeof window === 'undefined') return;
   try {
-    localStorage.setItem(CHECKLIST_KEY, JSON.stringify(Array.from(set)));
+    localStorage.setItem(CHECKLIST_KEY_V2, JSON.stringify(state));
   } catch {
     // ignore
   }