Resume pending action after login (favorite, diary, QR upload)

Add pendingAction callback to UI store. When user clicks favorite,
save-to-diary, or upload QR while not logged in, the action is stored
and automatically executed after successful login/register instead of
reloading the page.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/LoginModal.vue

@@ -104,8 +104,11 @@ async function submit() {
       ui.showToast('注册成功')
     }
     emit('close')
-    // Reload page data after auth change
+    if (ui.pendingAction) {
+      ui.runPendingAction()
+    } else {
       window.location.reload()
+    }
   } catch (e) {
     errorMsg.value = e?.message || (mode.value === 'login' ? '登录失败，请检查用户名和密码' : '注册失败，请重试')
   } finally {

frontend/src/components/RecipeDetailOverlay.vue

@@ -490,7 +490,7 @@ const showBrandHint = computed(() =>
 
 function goUploadQr() {
   if (!authStore.isLoggedIn) {
-    ui.openLogin()
+    ui.openLogin(() => goUploadQr())
     return
   }
   if (recipe.value._id) {
@@ -606,7 +606,7 @@ function getCardRecipeName() {
 // ---- Favorite ----
 async function handleToggleFavorite() {
   if (!authStore.isLoggedIn) {
-    ui.openLogin()
+    ui.openLogin(() => handleToggleFavorite())
     return
   }
   if (!recipe.value._id) {
@@ -625,7 +625,7 @@ async function handleToggleFavorite() {
 // ---- Save to diary ----
 async function saveToDiary() {
   if (!authStore.isLoggedIn) {
-    ui.openLogin()
+    ui.openLogin(() => saveToDiary())
     return
   }
   const name = prompt('保存为我的配方，名称：', recipe.value.name)

frontend/src/stores/ui.js

@@ -5,6 +5,7 @@ export const useUiStore = defineStore('ui', () => {
   const currentSection = ref('search')
   const showLoginModal = ref(false)
   const toasts = ref([])
+  const pendingAction = ref(null)
 
   let toastId = 0
 
@@ -20,7 +21,10 @@ export const useUiStore = defineStore('ui', () => {
     }, duration)
   }
 
-  function openLogin() {
+  function openLogin(afterLogin) {
+    if (afterLogin) {
+      pendingAction.value = afterLogin
+    }
     showLoginModal.value = true
   }
 
@@ -28,13 +32,23 @@ export const useUiStore = defineStore('ui', () => {
     showLoginModal.value = false
   }
 
+  function runPendingAction() {
+    if (pendingAction.value) {
+      const action = pendingAction.value
+      pendingAction.value = null
+      action()
+    }
+  }
+
   return {
     currentSection,
     showLoginModal,
     toasts,
+    pendingAction,
     showSection,
     showToast,
     openLogin,
     closeLogin,
+    runPendingAction,
   }
 })