feat: 人工接管任务（takeover）+ 任务详情展示附件

B-③ takeover（⑧ ★ POST /api/tasks/:id/takeover）：

后端：
- POST /api/tasks/:id/takeover：准备（或复用 result.worktree）任务 worktree，
  返回 {taskId, worktree, branch, console}——console 为用户在自己终端起交互式
  claude 的命令（daemon 无 TTY，不在进程内起交互会话）；在途 run 时拒绝

前端：
- api.takeover；TakeoverModal（展示命令 + 一键复制 + 分支提示）
- TaskDetail 加「⌨ 人工接管」按钮（onTakeover 经 TaskSection→TaskRow 线程下来）
- 顺带：TaskDetail 展示任务附件（📎 文件名，读 task._raw.attachments）

验证：typecheck 干净；206 测试通过；前端 build + dev 渲染 0 错误。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

design/ui_kits/console/TaskTree.jsx

@@ -100,7 +100,7 @@ function FilterBar({ t, kw, setKw, cplxSet, toggleCplx, statusSet, toggleGroup,
   );
 }
 
-function TaskRow({ task, depth, ctx, expandedId, setExpandedId, openIds, toggleOpen, t, byId, cplxOf, onChangeCplx, flashId, onJump, visibleSet }) {
+function TaskRow({ task, depth, ctx, expandedId, setExpandedId, openIds, toggleOpen, t, byId, cplxOf, onChangeCplx, flashId, onJump, visibleSet, onTakeover }) {
   const { StatusChip } = window.MaestroDesignSystem_a6a290;
   const kids = (task.children || []).filter((k) => !visibleSet || visibleSet.has(k.id));
   const open = openIds.has(task.id) || !!visibleSet; // 筛选时自动展开可见节点
@@ -140,13 +140,13 @@ function TaskRow({ task, depth, ctx, expandedId, setExpandedId, openIds, toggleO
         <CplxPicker task={task} cplx={cplxOf(task)} onChange={onChangeCplx} />
         <StatusChip status={task.status} label={t.status[task.status]} />
       </div>
-      {expanded ? <TaskDetail task={task} t={t} byId={byId} onJump={onJump} /> : null}
+      {expanded ? <TaskDetail task={task} t={t} byId={byId} onJump={onJump} onTakeover={onTakeover} /> : null}
       {kids.length && open ? (
         <div style={{ marginLeft: 22 }}>
           {kids.map((k) => (
             <TaskRow key={k.id} task={k} depth={depth + 1} ctx={visibleSet ? visibleSet.ctx.has(k.id) : false}
               expandedId={expandedId} setExpandedId={setExpandedId} openIds={openIds} toggleOpen={toggleOpen} t={t}
-              byId={byId} cplxOf={cplxOf} onChangeCplx={onChangeCplx} flashId={flashId} onJump={onJump} visibleSet={visibleSet} />
+              byId={byId} cplxOf={cplxOf} onChangeCplx={onChangeCplx} flashId={flashId} onJump={onJump} visibleSet={visibleSet} onTakeover={onTakeover} />
           ))}
         </div>
       ) : null}
@@ -154,11 +154,25 @@ function TaskRow({ task, depth, ctx, expandedId, setExpandedId, openIds, toggleO
   );
 }
 
-function TaskDetail({ task, t, byId, onJump }) {
+function TaskDetail({ task, t, byId, onJump, onTakeover }) {
   const label = task.doc ? t.specLabel : task.ops ? t.opsLabel : null;
   const text = task.doc || task.ops;
+  const attachments = (task._raw && task._raw.attachments) || [];
   return (
     <div style={{ background: 'var(--panel)', borderBottom: '1px solid var(--line)', borderLeft: '2px solid var(--green-dim)', padding: '14px 16px', animation: 'maestro-rise .2s ease both', display: 'grid', gap: 14 }}>
+      {onTakeover || attachments.length ? (
+        <div style={{ display: 'flex', alignItems: 'center', gap: 10, flexWrap: 'wrap' }}>
+          {onTakeover ? (
+            <button onClick={(e) => { e.stopPropagation(); onTakeover(task); }}
+              style={{ fontFamily: 'var(--mono)', fontSize: 12, cursor: 'pointer', background: 'transparent', color: 'var(--cyan)', border: '1px solid var(--cyan-dim)', borderRadius: 'var(--radius-sm,4px)', padding: '3px 10px' }}>
+              ⌨ 人工接管
+            </button>
+          ) : null}
+          {attachments.length ? (
+            <span style={{ fontSize: 11, color: 'var(--faint)' }}>📎 {attachments.map((a) => a.name).join(' · ')}</span>
+          ) : null}
+        </div>
+      ) : null}
       {label ? (
         <div>
           <div style={{ fontSize: 10.5, color: 'var(--muted)', letterSpacing: '.18em', marginBottom: 4 }}>{label}</div>
@@ -253,7 +267,7 @@ function NewTaskPanel({ tasks, onCancel, onCreate, t }) {
   );
 }
 
-function TaskSection({ tasks, onToast, onCreate, t }) {
+function TaskSection({ tasks, onToast, onCreate, onTakeover, t }) {
   const { Button, SectionHead } = window.MaestroDesignSystem_a6a290;
   const [expandedId, setExpandedId] = React.useState(null);
   const [openIds, setOpenIds] = React.useState(() => new Set(['t1']));
@@ -333,7 +347,7 @@ function TaskSection({ tasks, onToast, onCreate, t }) {
         {roots.map((tk) => (
           <TaskRow key={tk.id} task={tk} depth={0} ctx={visibleSet ? visibleSet.ctx.has(tk.id) : false}
             expandedId={expandedId} setExpandedId={setExpandedId} openIds={openIds} toggleOpen={toggleOpen} t={t}
-            byId={byId} cplxOf={cplxOf} onChangeCplx={onChangeCplx} flashId={flashId} onJump={onJump} visibleSet={visibleSet} />
+            byId={byId} cplxOf={cplxOf} onChangeCplx={onChangeCplx} flashId={flashId} onJump={onJump} visibleSet={visibleSet} onTakeover={onTakeover} />
         ))}
       </div>
     </section>