feat: 创作主题保存/加载 + 支付二维码过期提示

- ScriptCreation: 大类/小类 selection 持久化到 project meta
- ProjectMeta: 新增 subcategoryCode 字段
- projectStore: 新增 setSubcategoryCode action
- localStorage: orderedMeta 补全 categoryCode/subcategoryCode
- RechargeModal: 过期后点击'我已支付'给出 toast 提示，按钮禁用并显示'二维码已过期'

tauri-app/src/api/modules/localStorage.ts

@@ -93,6 +93,8 @@ export const localProjectApi = {
       id: meta.id,
       title: meta.title,
       topic: meta.topic,
+      categoryCode: meta.categoryCode,
+      subcategoryCode: meta.subcategoryCode,
       status: meta.status,
       currentStep: meta.currentStep,
       createdAt: meta.createdAt,

tauri-app/src/components/RechargeModal/RechargeModal.tsx

@@ -179,10 +179,11 @@ export default function RechargeModal({
     const orderId = orderIdRef.current;
     if (!orderId) {return;}
 
-    // 二维码已过期，直接提示
-    if (Date.now() >= expireAtRef.current) {
+    // 二维码已过期，明确提示用户
+    if (isExpired || Date.now() >= expireAtRef.current) {
       clearTimers();
       setIsExpired(true);
+      toast.info('二维码已过期，请点击刷新二维码或重新下单');
       return;
     }
 
@@ -353,9 +354,9 @@ export default function RechargeModal({
           <button
             className="btn btn-primary"
             onClick={handleQueryPayment}
-            disabled={isLoading}
+            disabled={isLoading || isExpired}
           >
-            {isLoading ? '查询中...' : '我已支付'}
+            {isLoading ? '查询中...' : isExpired ? '二维码已过期' : '我已支付'}
           </button>
           <button
             className="btn btn-ghost"

tauri-app/src/pages/VideoCreation/ScriptCreation.tsx

@@ -21,8 +21,11 @@ export default function ScriptCreation() {
   const segments = useProjectStore(state => state.segments);
   const setSegments = useProjectStore(state => state.setSegments);
   const updateSegment = useProjectStore(state => state.updateSegment);
+  const categoryCode = useProjectStore(state => state.categoryCode);
+  const subcategoryCode = useProjectStore(state => state.subcategoryCode);
   const setTopic = useProjectStore(state => state.setTopic);
   const setCategoryCode = useProjectStore(state => state.setCategoryCode);
+  const setSubcategoryCode = useProjectStore(state => state.setSubcategoryCode);
 
   const [generating, setGenerating] = useState(false);
   const requestLock = useRef(false);
@@ -30,8 +33,8 @@ export default function ScriptCreation() {
   // 分类列表（从后端动态加载）
   const [categories, setCategories] = useState<CategoryItem[]>([]);
   // 选中的大类和小类
-  const [selectedCategory, setSelectedCategory] = useState<string>('');
-  const [selectedSubcategory, setSelectedSubcategory] = useState<string>('');
+  const [selectedCategory, setSelectedCategory] = useState<string>(categoryCode || '');
+  const [selectedSubcategory, setSelectedSubcategory] = useState<string>(subcategoryCode || '');
 
   // 加载分类列表（带本地缓存 + 静默刷新）
   useEffect(() => {
@@ -50,6 +53,22 @@ export default function ScriptCreation() {
       });
   }, []);
 
+  // 分类列表加载后，恢复之前保存的选中状态
+  useEffect(() => {
+    if (categories.length === 0) {return;}
+    if (categoryCode && subcategoryCode) {
+      // 验证保存的 code 是否在当前分类列表中有效
+      const catExists = categories.some(c => c.code === categoryCode);
+      const subExists = categories.some(c =>
+        c.code === categoryCode && c.subcategories.some(s => s.code === subcategoryCode)
+      );
+      if (catExists && subExists) {
+        setSelectedCategory(categoryCode);
+        setSelectedSubcategory(subcategoryCode);
+      }
+    }
+  }, [categories, categoryCode, subcategoryCode]);
+
   // 编辑状态：存储正在编辑的字段键（如 "1-scene", "2-voiceover"）
   const [editingFields, setEditingFields] = useState<Set<string>>(new Set());
 
@@ -336,6 +355,7 @@ export default function ScriptCreation() {
                       setSelectedSubcategory(sub.code);
                       setTopic(sub.name);
                       setCategoryCode(cat.code);
+                      setSubcategoryCode(sub.code);
                     }}
                   >
                     {sub.name}

tauri-app/src/store/projectStore.ts

@@ -31,6 +31,7 @@ interface ProjectActions {
   setVoiceVolume: (_volume: number) => void;
   setVoicePitch: (_pitch: number) => void;
   setCategoryCode: (_code: string) => void;
+  setSubcategoryCode: (_code: string) => void;
   setIsLoading: (_loading: boolean) => void;
   setHasHydrated: (_hydrated: boolean) => void;
 }
@@ -231,6 +232,13 @@ export const useProjectStore = create<ProjectStore>()(
           });
           saveMetaToLocalFile({ categoryCode: code });
         },
+        setSubcategoryCode: code => {
+          set(state => {
+            state.subcategoryCode = code;
+            state.updatedAt = Date.now();
+          });
+          saveMetaToLocalFile({ subcategoryCode: code });
+        },
 
       }),
       {

tauri-app/src/types/project.ts

@@ -82,6 +82,7 @@ export interface ProjectMeta {
   // === 创作参数 ===
   topic?: string;
   categoryCode?: string;
+  subcategoryCode?: string;
 
   // === 素材选择 ===
   selectedVoiceId?: string;

tauri-app/src/utils/projectMeta.ts

@@ -140,6 +140,7 @@ export function migrateMeta(raw: unknown): Partial<ProjectMeta> {
 export const BLANK_META_OVERRIDES: MetaOverrides = {
   topic: undefined,
   categoryCode: undefined,
+  subcategoryCode: undefined,
   selectedVoiceId: undefined,
   finalVideoPath: undefined,
   coverPath: undefined,