feat(content): 分组对所有内容类型生效，统一分区/分组/条目模型

- 分区=容器，分组=任意类型的可选子容器，条目可挂分区或分组（直属分区）
- catalog 所有类型统一输出 groups + items，条目查询按节点取
- 详情/侧栏/首页卡片预览支持所有类型的分组；多组显示小标题 + 未分组
- 后台「分区」「侧栏导航」对所有类型可建组；「内容」弹窗分组可选直属分区，编辑可换组
- 修复首页卡片配置为「整个分区」时预览为空
- 测试 59 passed

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

@@ -503,7 +503,7 @@ function SidebarForm({
 
       {ordered.map((category, index) => {
         const visible = !value.hidden.includes(category.id)
-        const groups = category.kind === 'apps' ? orderedGroups(category) : []
+        const groups = orderedGroups(category)
 
         return (
           <div className="admin-nav-block" key={category.id}>
@@ -539,7 +539,7 @@ function SidebarForm({
               </div>
             ))}
 
-            {category.kind === 'apps' && (
+            {(
               <div className="admin-nav-group-row">
                 <NewGroupRow sectionId={category.id} onReload={onReload} />
               </div>
@@ -762,12 +762,8 @@ function CategoryManager({
             onReload={onReload}
             onDelete={onDelete}
           />
-          {category.kind === 'apps' && (
-            <>
-              <BlockSelect section={category} onReload={onReload} />
-              <GroupManager section={category} onReload={onReload} />
-            </>
-          )}
+          <BlockSelect section={category} onReload={onReload} />
+          <GroupManager section={category} onReload={onReload} />
         </div>
       ))}
 
@@ -1094,20 +1090,21 @@ function ContentManager({
   const entries: EntryRow[] =
     section === undefined
       ? []
-      : section.kind === 'apps'
-        ? (section.groups ?? []).flatMap((group) =>
+      : [
+          ...(section.groups ?? []).flatMap((group) =>
             (group.items ?? []).map((item) => ({
               ...item,
               groupName: group.name,
               sectionId: section.id,
               groupId: group.id,
             })),
-          )
-        : (section.items ?? []).map((item) => ({
+          ),
+          ...(section.items ?? []).map((item) => ({
             ...item,
             groupName: undefined,
             sectionId: section.id,
-          }))
+          })),
+        ]
 
   const removeEntry = async () => {
     if (pendingEntry === null) return
@@ -1274,7 +1271,7 @@ function EntryDialog({
 
   const section =
     categories.find((category) => category.id === sectionId) ?? categories[0]
-  const groups = section?.kind === 'apps' ? (section.groups ?? []) : []
+  const groups = section?.groups ?? []
 
   // 打开时重置：新建用当前选择，编辑先拉完整条目
   useEffect(() => {
@@ -1284,7 +1281,11 @@ function EntryDialog({
     const startSection =
       defaultLocation?.sectionId ?? categories[0]?.id ?? ''
     setSectionId(startSection)
-    setGroupId(defaultLocation?.groupId ?? '')
+    setGroupId(
+      defaultLocation?.groupId ??
+        categories.find((category) => category.id === startSection)?.groups?.[0]?.id ??
+        '',
+    )
 
     if (entryKey === null) {
       setLoading(false)
@@ -1321,19 +1322,16 @@ function EntryDialog({
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [open, entryKey])
 
-  // 分区切换后保证分组仍然合法
+  // 分区切换后保证分组仍然合法（空字符串 = 直属分区）
   useEffect(() => {
-    if (section?.kind !== 'apps') {
-      setGroupId('')
-      return
-    }
-    if (!groups.some((group) => group.id === groupId)) {
+    if (section === undefined) return
+    if (groupId !== '' && !groups.some((group) => group.id === groupId)) {
       setGroupId(groups[0]?.id ?? '')
     }
   }, [section, groups, groupId])
 
   const nodeKey =
-    section === undefined ? '' : section.kind === 'apps' ? groupId : section.id
+    section === undefined ? '' : groupId !== '' ? groupId : section.id
 
   const update = (patch: Partial<EntryForm>) =>
     setForm((previous) => ({ ...previous, ...patch }))
@@ -1430,13 +1428,16 @@ function EntryDialog({
                 onChange={setSectionId}
               />
             </div>
-            {section?.kind === 'apps' && (
-              <div style={{ width: 220 }}>
+            {section !== undefined && (
+              <div style={{ width: 240 }}>
                 <Select
-                  options={groups.map((group) => ({
-                    value: group.id,
-                    label: group.name,
-                  }))}
+                  options={[
+                    { value: '', label: '直属分区（不分组）' },
+                    ...groups.map((group) => ({
+                      value: group.id,
+                      label: group.name,
+                    })),
+                  ]}
                   value={groupId}
                   onChange={setGroupId}
                 />