feat(edit): P2 条目就地编辑 + P3 备份/审计/改密

- 迁移 v17：entry.updated_at（乐观锁）+ audit 表
- GET/PATCH /api/items/{key}：字段编辑、标签替换、409 冲突、400 校验
- 详情页 [编辑] → Drawer 表单（标题/简介/标签/评价/正文/封面/跳转），保存后局部刷新
- GET /api/backup：VACUUM INTO 一致性快照，附件下载
- /admin 系统 Tab：修改密码（清空会话）、下载备份
- 审计：item.update / settings.update
- 测试 46 passed（entries 4 例）
- 文档：ADMIN-PLAN P2/P3 记录、README

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

@@ -15,6 +15,7 @@ type ArticleDetailViewProps = {
   categoryId: string
   categoryTitle: string
   onNavigate: (href: string) => void
+  onEdit: () => void
 }
 
 export function ArticleDetailView({
@@ -22,6 +23,7 @@ export function ArticleDetailView({
   categoryId,
   categoryTitle,
   onNavigate,
+  onEdit,
 }: ArticleDetailViewProps) {
   const meta = article.meta ?? ['2 年前', categoryTitle]
   const crumbs = [
@@ -39,7 +41,7 @@ export function ArticleDetailView({
       <header className="article-head">
         <Title level={1} as="h2" className="article-heading">
           {article.title}
-          <button type="button" className="item-edit" disabled title="编辑功能待接入">
+          <button type="button" className="item-edit" title="编辑文章" onClick={onEdit}>
             [编辑]
           </button>
         </Title>

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

@@ -27,6 +27,8 @@ type ItemDetailViewProps = {
   related: RelatedItem[]
   onNavigate: (href: string) => void
   onOpenItem: (itemId: string) => void
+  /** 打开编辑 Drawer */
+  onEdit: () => void
 }
 
 export function ItemDetailView({
@@ -35,6 +37,7 @@ export function ItemDetailView({
   related,
   onNavigate,
   onOpenItem,
+  onEdit,
 }: ItemDetailViewProps) {
   return (
     <div className="detail-view item-view">
@@ -45,7 +48,7 @@ export function ItemDetailView({
       <Card padding="none" className="item-card">
         <Title level={1} as="h2" weight="semibold" className="item-title">
           {model.title}
-          <button type="button" className="item-edit" disabled title="编辑功能待接入">
+          <button type="button" className="item-edit" title="编辑条目" onClick={onEdit}>
             [编辑]
           </button>
         </Title>

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

@@ -0,0 +1,203 @@
+import { Button, Drawer, FormField, Icon, Input, Notice, Space, Textarea } from '@stash/ui'
+import { useEffect, useState } from 'react'
+import { fetchItem, saveItem, type EntryRecord } from '../../items'
+
+/**
+ * 条目编辑器（P2）：右侧 Drawer 表单，就地改标题 / 简介 / 标签 / 正文等。
+ *
+ * `updatedAt` 做乐观锁：别人先改过就提示刷新，避免静默覆盖。
+ */
+type ItemEditorProps = {
+  open: boolean
+  itemKey: string | null
+  onClose: () => void
+  onSaved: (entry: EntryRecord) => void
+}
+
+type FormState = {
+  name: string
+  description: string
+  tags: string
+  badge: string
+  comment: string
+  summary: string
+  body: string
+  cover: string
+  banner: string
+  href: string
+}
+
+const emptyForm: FormState = {
+  name: '',
+  description: '',
+  tags: '',
+  badge: '',
+  comment: '',
+  summary: '',
+  body: '',
+  cover: '',
+  banner: '',
+  href: '',
+}
+
+export function ItemEditor({ open, itemKey, onClose, onSaved }: ItemEditorProps) {
+  const [entry, setEntry] = useState<EntryRecord | null>(null)
+  const [form, setForm] = useState<FormState>(emptyForm)
+  const [loading, setLoading] = useState(false)
+  const [saving, setSaving] = useState(false)
+  const [error, setError] = useState('')
+
+  useEffect(() => {
+    if (!open || itemKey === null) return
+
+    let alive = true
+    setLoading(true)
+    setError('')
+    fetchItem(itemKey).then((result) => {
+      if (!alive) return
+      setLoading(false)
+      if (!result.ok) {
+        setError(result.error)
+        return
+      }
+
+      const next = result.entry
+      setEntry(next)
+      setForm({
+        name: next.name,
+        description: next.description,
+        tags: next.tags.join('，'),
+        badge: next.badge,
+        comment: next.comment,
+        summary: next.summary,
+        body: next.body,
+        cover: next.cover,
+        banner: next.banner,
+        href: next.href,
+      })
+    })
+
+    return () => {
+      alive = false
+    }
+  }, [open, itemKey])
+
+  const update = (patch: Partial<FormState>) => setForm((previous) => ({ ...previous, ...patch }))
+
+  const save = async () => {
+    if (entry === null) return
+    setSaving(true)
+    setError('')
+
+    const result = await saveItem(entry.key, entry.updated_at, {
+      ...form,
+      tags: form.tags
+        .split(/[，,]/)
+        .map((tag) => tag.trim())
+        .filter(Boolean),
+    })
+
+    setSaving(false)
+    if (!result.ok) {
+      setError(result.error)
+      return
+    }
+
+    onSaved(result.entry)
+    onClose()
+  }
+
+  return (
+    <Drawer
+      open={open}
+      onClose={onClose}
+      width={520}
+      title="编辑条目"
+      footer={
+        <Space gap="sm" justify="end">
+          <Button variant="secondary" onClick={onClose}>
+            取消
+          </Button>
+          <Button
+            loading={saving}
+            disabled={loading}
+            icon={<Icon name="check_line" />}
+            onClick={save}
+          >
+            保存
+          </Button>
+        </Space>
+      }
+    >
+      {loading && <p>正在读取…</p>}
+      {error !== '' && (
+        <Notice tone="error" title="保存失败">
+          {error}
+        </Notice>
+      )}
+
+      {!loading && entry !== null && (
+        <Space direction="column" gap="md" align="stretch">
+          <FormField label="标题" htmlFor="edit-name" required>
+            <Input
+              id="edit-name"
+              value={form.name}
+              onChange={(event) => update({ name: event.target.value })}
+            />
+          </FormField>
+
+          <FormField label="简介" htmlFor="edit-description" hint="列表卡片上的一行说明">
+            <Input
+              id="edit-description"
+              value={form.description}
+              onChange={(event) => update({ description: event.target.value })}
+            />
+          </FormField>
+
+          <FormField label="标签" htmlFor="edit-tags" hint="用逗号分隔，例如：推荐电影，动画">
+            <Input
+              id="edit-tags"
+              value={form.tags}
+              onChange={(event) => update({ tags: event.target.value })}
+            />
+          </FormField>
+
+          <FormField label="一句话评价" htmlFor="edit-comment">
+            <Input
+              id="edit-comment"
+              value={form.comment}
+              onChange={(event) => update({ comment: event.target.value })}
+            />
+          </FormField>
+
+          <FormField label="正文" htmlFor="edit-body" hint="支持 Markdown：##、段落、链接、图片">
+            <Textarea
+              id="edit-body"
+              rows={8}
+              value={form.body}
+              onChange={(event) => update({ body: event.target.value })}
+            />
+          </FormField>
+
+          <FormField label="封面地址" htmlFor="edit-cover">
+            <Input
+              id="edit-cover"
+              value={form.cover}
+              placeholder="https://…"
+              onChange={(event) => update({ cover: event.target.value })}
+            />
+          </FormField>
+
+          <FormField label="跳转地址" htmlFor="edit-href">
+            <Input
+              id="edit-href"
+              value={form.href}
+              placeholder="https://…"
+              onChange={(event) => update({ href: event.target.value })}
+            />
+          </FormField>
+        </Space>
+      )}
+    </Drawer>
+  )
+}