feat(tasks): 任务窗内容填满高度可自然拉伸；聚合卡在成员多时报出 +N

用户两条优化：
  1. 任务详细占满上下部分，不要留空(这样能自然拉伸)
  2. 思考如何优化内容很多时的待命和完成的样式

第 1 条：描述区原本是 `max-height: 160px` 的滚动盒，窗口拉大只长空白。
FloatingWindow 新增 `bodyLayout: 'scroll' | 'fill'`（默认 scroll 不变，后台
任务输出窗仍按原样流动），fill 把 body 变成列容器、让调用方的子节点自己决定
谁吃余量；任务窗据此把余量全给描述区（编辑态给多行输入框，`flex: 1` 跟着窗
口长），头部行 / 元信息 / 负责人 / 提示行都 `flex: none`，不会跟着漂。

第 2 条：一队队友很多时，聚合卡只有一行名字却塞了十几个人，卡上看不出还有
多少。名称行现在写「前两个名字 + N」—— 用的是团队任务行已有的同一个 `+N`
约定，不是第二套；分组总数另有徽标和小条两处，所以 `+N` 只是尾巴而不是唯一
计数。图卡片与树行共用同一个 foldPreviews。

测试：新增 2 例（窗口声明 fill 布局、描述区在 body 内且编辑态换成多行框；
五个待命成员的聚合卡名称是 `m1 / m2 +3`）；floating-window 既有 9 例回归通过。
pnpm test 1288 passed / 9 skipped，typecheck / lint 通过。

(cherry picked from commit 62651e731d6e5fd0378e2ecc504792cb2e3eb461)

src/client/FloatingWindow.module.css

@@ -77,6 +77,20 @@
   padding: 10px 12px 12px;
 }
 
+/* A body whose content should FILL the window instead of stacking from the top
+   (a form with one editable region, a detail view with prose): the caller's
+   children become a column and decide for themselves what takes the slack, so
+   dragging the window bigger grows the content rather than the empty space. */
+.bodyFill {
+  display: flex;
+  flex-direction: column;
+}
+
+.bodyFill > * {
+  flex: 1;
+  min-height: 0;
+}
+
 .footer {
   display: flex;
   align-items: center;

src/client/FloatingWindow.tsx

@@ -83,6 +83,14 @@ export interface FloatingWindowProps {
    * caller scrolls it; the window owns its size and its overflow.
    */
   bodyRef?: RefObject<HTMLDivElement>
+  /**
+   * How the body stacks its children. `scroll` (default) flows them from the
+   * top inside the scrolling box — right for a log or a table. `fill` makes
+   * the body a column whose children stretch to the window's height — right
+   * for a detail view or a form, where the point of enlarging the window is
+   * more room for the content, not more empty space under it.
+   */
+  bodyLayout?: 'scroll' | 'fill'
   children: ReactNode
 }
 
@@ -143,7 +151,9 @@ function initialBox(
  * two drag gestures and the dismissal contract (close button + Escape only).
  */
 export function FloatingWindow(props: FloatingWindowProps): ReactNode {
-  const { title, onClose, initialSize, minSize, anchor, actions, footer, bodyRef, children } = props
+  const {
+    title, onClose, initialSize, minSize, anchor, actions, footer, bodyRef, bodyLayout, children,
+  } = props
   const min = useMemo(() => ({
     width: minSize?.width ?? DEFAULT_MIN_WIDTH,
     height: minSize?.height ?? DEFAULT_MIN_HEIGHT,
@@ -304,7 +314,12 @@ export function FloatingWindow(props: FloatingWindowProps): ReactNode {
           />
         </span>
       </div>
-      <div ref={bodyRef} className={css.body} data-window-body>
+      <div
+        ref={bodyRef}
+        className={bodyLayout === 'fill' ? `${css.body} ${css.bodyFill}` : css.body}
+        data-window-body
+        data-window-body-layout={bodyLayout ?? 'scroll'}
+      >
         {children}
       </div>
       {footer !== undefined && <div className={css.footer} data-window-footer>{footer}</div>}

src/client/TaskWindow.tsx

@@ -121,7 +121,7 @@ function TaskViewBody(props: {
           </>
         )}
       </div>
-      <div className={css.taskMarkdown}>
+      <div className={css.taskMarkdown} data-task-description>
         {body === ''
           ? <div className={css.popHint}>{t('teamTaskNoDescription')}</div>
           : (
@@ -316,6 +316,9 @@ export function TaskWindow(props: TaskWindowProps): ReactNode {
       initialSize={{ width: 460, height: 360 }}
       minSize={{ width: 320, height: 240 }}
       anchor={props.anchor}
+      // The description (or the editor) owns the window's slack: enlarging it
+      // gives the CONTENT more room instead of leaving a gap under it.
+      bodyLayout="fill"
       footer={(
         // The action row is the shell's FOOTER, so it never scrolls away from
         // the body it acts on. One state owner: `busy` and `armedDelete` are
@@ -436,6 +439,7 @@ export function TaskWindow(props: TaskWindowProps): ReactNode {
         </div>
       )}
     >
+      <div className={css.taskBody}>
       <div className={css.taskHeadRow}>
         {task !== undefined && <StateDot size={6} state={taskDotState(task)} />}
         <span className={css.popTitle} title={task?.subject ?? subject}>
@@ -466,6 +470,7 @@ export function TaskWindow(props: TaskWindowProps): ReactNode {
         )}
 
       {note !== undefined && <div className={css.teamNote}>{note}</div>}
+      </div>
     </FloatingWindow>
   )
 }

src/client/TasksGraph.tsx

@@ -678,7 +678,7 @@ function renderFoldNode(
         count={node.count}
         foldKind={node.foldKind}
         depth={node.depth}
-        name={foldPreviews(node.previews)}
+        name={foldPreviews(node.previews, node.count)}
         extraClass={css.cardNamePlain}
       />
       <CardBar state={node.foldKind === 'idle' ? 'idle' : 'done'} stateWord={false}>

src/client/TasksTree.tsx

@@ -117,8 +117,8 @@ export function TasksTree(props: TasksTreeProps): ReactNode {
                 {t(folded ? 'tasksFoldExpand' : 'tasksFoldCollapse')}
               </span>
             </span>
-            <span className={css.treeMeta} title={foldPreviews(node.previews)}>
-              {foldPreviews(node.previews)}
+            <span className={css.treeMeta} title={foldPreviews(node.previews, node.count)}>
+              {foldPreviews(node.previews, node.count)}
             </span>
           </span>
         </div>

src/client/tasks-graph.module.css

@@ -809,6 +809,16 @@
   min-width: 0;
 }
 
+/* The task window's body: the window hands it the slack (FloatingWindow's
+   `fill` layout), and inside it the description / editor is the region that
+   grows. Everything else keeps its natural height so the action row and the
+   meta line never drift. */
+.taskBody {
+  display: flex;
+  flex-direction: column;
+  min-height: 0;
+}
+
 /* The task window's own head line (inside the floating window's scrolling
    body): state dot + subject + status Tag. Sentence case, unlike the node
    detail's letter-spaced uppercase `.popHead` band — this one labels a real
@@ -1035,8 +1045,12 @@
  * task / output wells beside it, and the body is the card's VALUE rung
  * (secondary) — a description is content, not a title, so the title keeps the
  * card's only primary ink. */
+/* The description: it FILLS the window (no 160px cap — that was the box that
+   left the rest of a resized window empty) and scrolls inside itself only when
+   the prose really is longer than the room. */
 .taskMarkdown {
-  max-height: 160px;
+  flex: 1;
+  min-height: 0;
   overflow-y: auto;
   padding: 2px 0;
   font: var(--dsw-font-xxs-12);
@@ -1130,6 +1144,7 @@
 
 .taskTextarea {
   width: 100%;
+  flex: 1;
   min-height: 120px;
   padding: 6px 8px;
   border: 1px solid var(--dsw-alias-border-l2);
@@ -1152,11 +1167,19 @@
 
 /* The form's two field groups keep the card's OWN beat: 8px between groups
    against the 4px between a label and its control, so view and edit stack on
-   the same rhythm (the view's owner field carries the same 8px above it). */
+   the same rhythm (the view's owner field carries the same 8px above it).
+   The description group is the one that grows with the window. */
 .taskForm {
   display: flex;
   flex-direction: column;
   gap: 8px;
+  flex: 1;
+  min-height: 0;
+}
+
+.taskForm > label:last-child {
+  flex: 1;
+  min-height: 0;
 }
 
 .taskField {
@@ -1171,6 +1194,15 @@
   margin-top: 4px;
 }
 
+/* The owner field is a fixed band under the description: it must not absorb
+   the window's slack (the prose is what grows). */
+.taskBody > .taskField,
+.taskBody > .jobPopMeta,
+.taskBody > .taskHeadRow,
+.taskBody > .teamNote {
+  flex: none;
+}
+
 .taskLabel {
   font-family: var(--ds-font-family-code, monospace);
   font-size: 10px;

src/client/tasks-shared.tsx

@@ -282,9 +282,22 @@ export function LiveLine(props: { live: SidebarChildLiveView | undefined }): Rea
   )
 }
 
-/** The fold aggregate's subtitle: up to two label previews joined by `/`. */
-export function foldPreviews(previews: readonly string[]): string {
-  return previews.join(' / ')
+/**
+ * The fold aggregate's name line: two label previews, plus `+N` when the group
+ * holds more.
+ *
+ * A roster aggregate can swallow dozens of members, and the card has one line
+ * for them. Naming two and saying how many are left over is what keeps that
+ * line honest at any size — the exact `+N` the team task line already uses,
+ * not a second convention. The group's total is also on the badge and the bar,
+ * so `+N` is a tail, never the only count.
+ *
+ * @param previews - member labels, in page order (see {@link TasksFoldNode.previews}).
+ * @param count - how many members the group holds in total.
+ */
+export function foldPreviews(previews: readonly string[], count: number): string {
+  const tail = count > previews.length ? ` +${count - previews.length}` : ''
+  return `${previews.join(' / ')}${tail}`
 }
 
 /**

tests/tasks-model.spec.ts

@@ -16,7 +16,9 @@ import type {
   SidebarSubagentCatalogEntry,
 } from '../src/context-types.ts'
 import type { TeamMemberRow } from '../src/client/team-projection.ts'
-import { taskBlocked, taskDotState, taskStatusLabel, taskTone } from '../src/client/tasks-shared.tsx'
+import {
+  foldPreviews, taskBlocked, taskDotState, taskStatusLabel, taskTone,
+} from '../src/client/tasks-shared.tsx'
 import type { SubagentCatalogView } from '../src/client/subagent-catalog.ts'
 import type { SidebarChildLiveView } from '../src/context-types.ts'
 import type { WorkflowRunView } from '../src/workflow-runs.ts'
@@ -247,6 +249,21 @@ describe('buildTasksModel', () => {
     })
   })
 
+  it('names two members and counts the rest on the aggregate card', () => {
+    const mates = ['m1', 'm2', 'm3', 'm4', 'm5']
+    const model = buildTasksModel(input({
+      catalogs: {
+        root: catalog(mates.map(id => child(id))),
+        ...Object.fromEntries(mates.map(id => [id, catalog([])])),
+      },
+      byId: Object.fromEntries([['root', summary('root')], ...mates.map(id => [id, summary(id)])]),
+      teamMembers: mates.map(id => member({ id, name: id, status: 'idle' })),
+    }))
+    const fold = model.find(node => node.kind === 'fold')
+    expect(fold?.previews).toEqual(['m1', 'm2'])
+    expect(foldPreviews(fold?.previews ?? [], fold?.count ?? 0)).toBe('m1 / m2 +3')
+  })
+
   it('keeps two idle team members visible (below the threshold)', () => {
     const mates = ['m1', 'm2']
     const model = buildTasksModel(input({

tests/tasks-page.spec.tsx

@@ -723,6 +723,35 @@ describe('Tasks page: the shared task window', () => {
     await act(async () => { unmount() })
   })
 
+  it('hands the window slack to the description instead of leaving it empty', async () => {
+    withTeam({ tasks: [teamTask({ subject: '长描述', description: '第一行\n\n第二行' })] })
+    const store = makeStore(snapshotWithChildren(1))
+    const { container, unmount } = renderRoot(
+      createElement(SubagentView, { sessionId: 'root', active: true, ctx: makeCtx(store) }),
+    )
+    await act(async () => { await Promise.resolve() })
+    const row = container.querySelector('button[aria-label^="任务详情"]') as HTMLButtonElement
+    await act(async () => { row.click() })
+    const body = document.querySelector('[data-window-body]') as HTMLElement
+    // The body declares the FILL layout, so its child column (and the prose in
+    // it) grows with the window instead of stacking under a 160px box.
+    expect(body.getAttribute('data-window-body-layout')).toBe('fill')
+    const described = body.querySelector('[data-task-description]') as HTMLElement
+    expect(described).not.toBeNull()
+    expect(described.textContent).toContain('第一行')
+    expect(body.querySelector('textarea')).toBeNull()
+    // Editing swaps in the multi-line field INSIDE the same growing body (the
+    // action that switches modes lives in the shell's FOOTER, not the body).
+    const frame = document.querySelector('[data-floating-window]') as HTMLElement
+    const edit = [...frame.querySelectorAll('button')].find(button => button.textContent?.includes('编辑'))
+    await act(async () => { edit?.click() })
+    const area = body.querySelector('textarea') as HTMLTextAreaElement
+    expect(area).not.toBeNull()
+    expect(area.value).toBe('第一行\n\n第二行')
+    expect(document.querySelector('[data-floating-window]')).not.toBeNull()
+    await act(async () => { unmount() })
+  })
+
   it('closes the task window on Escape, never on an outside click', async () => {
     withTeam({ tasks: [teamTask()] })
     const store = makeStore(snapshotWithChildren(1))