feat: 新增草稿箱自动保存功能

- 编辑时自动保存到 localStorage（每5秒或输入后2秒）
- 打开添加弹框时检查是否有草稿并提示恢复
- 成功添加后清除草稿
- 弹框标题显示“已自动保存”指示器

xian_favor/api.py

@@ -848,6 +848,7 @@ INDEX_TEMPLATE = '''
                 <h5 class="modal-title">
                     <span id="addModalIcon"></span> 
                     <span id="addModalTitle">添加条目</span>
+                    <span id="draftIndicator" class="badge bg-secondary ms-2" style="display:none;">已自动保存</span>
                 </h5>
                 <button type="button" class="btn-close" data-bs-dismiss="modal"></button>
             </div>
@@ -1531,6 +1532,129 @@ function changeSort() {
 // ============ 添加功能 ============
 
 // 快捷添加按钮
+// ============ 草稿箱 ============
+
+const DRAFT_KEY = 'xian_favor_draft';
+let draftTimer = null;
+
+// 保存草稿到 localStorage
+function saveDraft() {
+    const type = document.getElementById('addType')?.value || 'text';
+    const draft = {
+        type,
+        title: document.getElementById('addTitle')?.value || '',
+        content: document.getElementById('addContent')?.value || '',
+        url: document.getElementById('addUrl')?.value || '',
+        source: document.getElementById('addSource')?.value || '',
+        status: document.getElementById('addStatus')?.value || 'pending',
+        priority: document.getElementById('addPriority')?.value || 'medium',
+        due_date: document.getElementById('addDueDate')?.value || '',
+        note: document.getElementById('addNote')?.value || '',
+        tags: document.getElementById('addTags')?.value || '',
+        is_starred: document.getElementById('addStarred')?.checked || false,
+        saved_at: new Date().toISOString()
+    };
+    
+    // 只在有内容时保存
+    if (draft.title || draft.content || draft.url || draft.note) {
+        localStorage.setItem(DRAFT_KEY, JSON.stringify(draft));
+        showDraftIndicator();
+    }
+}
+
+// 加载草稿
+function loadDraft() {
+    const draft = localStorage.getItem(DRAFT_KEY);
+    if (!draft) return null;
+    return JSON.parse(draft);
+}
+
+// 清除草稿
+function clearDraft() {
+    localStorage.removeItem(DRAFT_KEY);
+    hideDraftIndicator();
+}
+
+// 显示草稿指示器
+function showDraftIndicator() {
+    const indicator = document.getElementById('draftIndicator');
+    if (indicator) indicator.style.display = 'inline';
+}
+
+// 隐藏草稿指示器
+function hideDraftIndicator() {
+    const indicator = document.getElementById('draftIndicator');
+    if (indicator) indicator.style.display = 'none';
+}
+
+// 检查是否有草稿并提示恢复
+function checkAndRestoreDraft(type) {
+    const draft = loadDraft();
+    if (!draft) return false;
+    
+    // 草稿类型匹配才提示
+    if (draft.type === type && (draft.title || draft.content || draft.url || draft.note)) {
+        const savedTime = new Date(draft.saved_at).toLocaleString('zh-CN');
+        if (confirm(`发现未保存的草稿（${savedTime}），是否恢复？`)) {
+            restoreDraftToForm(draft);
+            return true;
+        } else {
+            clearDraft();  // 用户选择不恢复，清除草稿
+        }
+    }
+    return false;
+}
+
+// 将草稿恢复到表单
+function restoreDraftToForm(draft) {
+    document.getElementById('addTitle').value = draft.title || '';
+    if (draft.type === 'text') {
+        document.getElementById('addContent').value = draft.content || '';
+    }
+    if (['link', 'column'].includes(draft.type)) {
+        document.getElementById('addUrl').value = draft.url || '';
+    }
+    if (draft.type === 'column') {
+        document.getElementById('addSource').value = draft.source || '';
+    }
+    if (draft.type === 'todo') {
+        document.getElementById('addStatus').value = draft.status || 'pending';
+        document.getElementById('addPriority').value = draft.priority || 'medium';
+        document.getElementById('addDueDate').value = draft.due_date || '';
+    }
+    document.getElementById('addNote').value = draft.note || '';
+    document.getElementById('addTags').value = draft.tags || '';
+    document.getElementById('addStarred').checked = draft.is_starred || false;
+    showDraftIndicator();
+}
+
+// 启动自动保存
+function startAutoSave() {
+    // 每5秒自动保存一次
+    draftTimer = setInterval(saveDraft, 5000);
+    
+    // 监听输入事件立即保存（带延迟）
+    const form = document.getElementById('addForm');
+    if (form) {
+        form.addEventListener('input', () => {
+            clearTimeout(draftTimer);
+            draftTimer = setTimeout(saveDraft, 2000);  // 输入后2秒保存
+            // 重新启动定时保存
+            clearInterval(draftTimer);
+            draftTimer = setInterval(saveDraft, 5000);
+        });
+    }
+}
+
+// 停止自动保存
+function stopAutoSave() {
+    if (draftTimer) {
+        clearInterval(draftTimer);
+        clearTimeout(draftTimer);
+        draftTimer = null;
+    }
+}
+
 function showAddModal(type) {
     // 设置类型
     document.getElementById('addType').value = type;
@@ -1555,8 +1679,19 @@ function showAddModal(type) {
     // 清空表单
     document.getElementById('addForm').reset();
     
+    // 检查是否有草稿
+    const restored = checkAndRestoreDraft(type);
+    
     // 打开弹窗
     new bootstrap.Modal(document.getElementById('addModal')).show();
+    
+    // 启动自动保存
+    startAutoSave();
+    
+    // 弹框关闭时停止自动保存
+    document.getElementById('addModal').addEventListener('hidden.bs.modal', () => {
+        stopAutoSave();
+    }, { once: true });
 }
 
 // 添加条目
@@ -1585,6 +1720,8 @@ async function addItem() {
     if (res.ok) {
         bootstrap.Modal.getInstance(document.getElementById('addModal')).hide();
         document.getElementById('addForm').reset();
+        clearDraft();  // 成功添加后清除草稿
+        stopAutoSave();  // 停止自动保存
         refreshData();
     }
 }