feat: 格式从分组下沉到条目（v21）

- entry 新增 format（apps/posters/articles），老数据按根分组 view_mode 回填；seed 按分区写入
- 分组管理移除格式字段/显示，根分组只作容器
- 内容弹窗新增逐条格式选择，列表增加格式列；ItemEditor 保存时保留原格式
- 前台按 entry.format 渲染：卡片/分组页支持同组混合格式，详情按条目格式选模板
- 迁移后 live 20 应用 / 13 海报；cargo test 59 passed；Playwright 验证混合展示

stash-web/src/components/admin/AdminNext.tsx

@@ -499,7 +499,6 @@ function GroupsPanel({
                       )}
                       <GroupMark icon={node.icon} />
                       <span className="group-name">{node.title}</span>
-                      <span className="group-format">{FORMAT_LABEL[node.format]}</span>
                     </div>
                   </td>
                   <td className="group-sort">{node.sort}</td>
@@ -583,7 +582,6 @@ function GroupDialog({
   const [key, setKey] = useState('')
   const [title, setTitle] = useState('')
   const [parentKey, setParentKey] = useState('')
-  const [format, setFormat] = useState<GroupFormat>('apps')
   const [icon, setIcon] = useState('')
   const [sort, setSort] = useState('')
   const [enabled, setEnabled] = useState(true)
@@ -599,7 +597,6 @@ function GroupDialog({
       setKey(state.group.key)
       setTitle(state.group.title)
       setParentKey(state.group.parentKey ?? '')
-      setFormat(state.group.format)
       setIcon(state.group.icon)
       setSort(String(state.group.sort))
       setEnabled(state.group.enabled)
@@ -608,7 +605,6 @@ function GroupDialog({
 
     setKey('')
     setTitle('')
-    setFormat('apps')
     setIcon('')
     setSort('')
     setEnabled(true)
@@ -625,7 +621,6 @@ function GroupDialog({
 
   const rootMode = parentKey === '' || isRootEdit
   const showKey = editing === undefined
-
   const submit = async () => {
     if (title.trim() === '') {
       setError('分组名称不能为空')
@@ -645,9 +640,7 @@ function GroupDialog({
         icon,
         sort: sort.trim() === '' ? undefined : Number(sort),
         enabled,
-        ...(isRootEdit
-          ? { format }
-          : { parentKey: parentKey }),
+        ...(isRootEdit ? {} : { parentKey }),
       })
       setBusy(false)
       if (!result.ok) {
@@ -663,7 +656,6 @@ function GroupDialog({
       key: key.trim(),
       title: title.trim(),
       parentKey: rootMode ? undefined : parentKey,
-      format: rootMode ? format : undefined,
       icon,
       sort: sort.trim() === '' ? undefined : Number(sort),
       enabled,
@@ -750,16 +742,6 @@ function GroupDialog({
           </FormField>
         )}
 
-        {rootMode && (
-          <FormField label="格式" htmlFor="group-format" hint="根分组决定这一棵树的渲染格式">
-            <Select
-              options={FORMAT_OPTIONS}
-              value={format}
-              onChange={(next) => setFormat(next as GroupFormat)}
-            />
-          </FormField>
-        )}
-
         <FormField label="图标样式" htmlFor="group-icon" hint="留空则不显示图标；可填 iconfont 图标名或一个字符">
           <div className="group-icon-field">
             <span className="group-icon-preview">
@@ -877,6 +859,7 @@ function ContentPanel({ groups, onReload }: { groups: GroupNode[]; onReload: ()
           <thead>
             <tr>
               <th>标题</th>
+              <th className="entry-col-format">格式</th>
               <th className="entry-col-href">跳转链接</th>
               <th className="entry-col-group">所属分组</th>
               <th className="group-col-actions">操作</th>
@@ -888,6 +871,11 @@ function ContentPanel({ groups, onReload }: { groups: GroupNode[]; onReload: ()
                 <td>
                   <span className="entry-title">{entry.name ?? entry.title ?? entry.id}</span>
                 </td>
+                <td>
+                  <span className="entry-format">
+                    {FORMAT_LABEL[(entry.format ?? 'apps') as GroupFormat]}
+                  </span>
+                </td>
                 <td>
                   <EntryLink href={entry.href} />
                 </td>
@@ -925,7 +913,7 @@ function ContentPanel({ groups, onReload }: { groups: GroupNode[]; onReload: ()
 
             {rows.length === 0 && (
               <tr>
-                <td colSpan={4} className="group-empty">
+                <td colSpan={5} className="group-empty">
                   该分组下还没有内容
                 </td>
               </tr>
@@ -972,6 +960,7 @@ function EntryDialog({
   const [error, setError] = useState('')
   const [form, setForm] = useState({
     key: '',
+    format: 'apps' as GroupFormat,
     name: '',
     href: '',
     icon: '',
@@ -994,6 +983,7 @@ function EntryDialog({
       setUpdatedAt(0)
       setForm({
         key: '',
+        format: 'apps',
         name: '',
         href: '',
         icon: '',
@@ -1016,6 +1006,7 @@ function EntryDialog({
       setUpdatedAt(result.entry.updated_at)
       setForm({
         key: result.entry.key,
+        format: result.entry.format,
         name: result.entry.name,
         href: result.entry.href,
         icon: result.entry.icon,
@@ -1044,6 +1035,7 @@ function EntryDialog({
     setBusy(true)
     setError('')
     const item = {
+      format: form.format,
       name: form.name.trim(),
       description: form.description,
       icon: form.icon,
@@ -1111,6 +1103,14 @@ function EntryDialog({
             />
           </div>
 
+          <FormField label="格式" htmlFor="entry-format" hint="每条内容单独选择格式，同一个分组下可以混合">
+            <Select
+              options={FORMAT_OPTIONS}
+              value={form.format}
+              onChange={(next) => update({ format: next as GroupFormat })}
+            />
+          </FormField>
+
           <FormField
             label="标识"
             htmlFor="entry-key"

stash-web/src/components/content/ItemEditor.tsx

@@ -91,6 +91,7 @@ export function ItemEditor({ open, itemKey, onClose, onSaved }: ItemEditorProps)
 
     const result = await saveItem(entry.key, entry.updated_at, {
       ...form,
+      format: entry.format,
       icon: entry.icon,
       tags: form.tags
         .split(/[，,]/)