fix: 长会话任务锚点重注入 + 过早 end_turn 提示,缓解任务跑偏

长会话反复无锚点催促("继续/接着做")会导致任务锚点衰减、模型过早
end_turn 打转。新增两层客户端护栏(均 token 友好):
- 层3 触发式锚点重注入:仅当最新用户消息是短的无锚点催促且存在未完成
  任务时,注入一次 ephemeral <system-reminder> 未完成任务清单(工具循环
  内不重复注入,无每轮成本)。
- 层2 过早 end_turn 提示:turn 自然完成且仍有 in_progress 任务时,显示
  0-token 本地 system 提示(不发给模型)。

Co-Authored-By: claude-opus-4-8[1m] <noreply@anthropic.com>

Author: universe-hcy

src/screens/REPL.tsx

@@ -3522,6 +3522,27 @@ export function REPL({
         onQueryEvent(event);
       }
 
+      // ── Unfinished-task notice ──
+      // When a turn completes naturally (not interrupted) but a task the model
+      // itself marked in_progress is still unfinished, surface a display-only
+      // local notice so the user doesn't have to blindly nudge "继续". This is a
+      // 'system' message: never sent to the model (0 token cost). Best-effort —
+      // a task-read failure must not affect turn teardown.
+      if (!abortController.signal.aborted) {
+        try {
+          const [{ listTasks, getTaskListId }, { buildUnfinishedTaskNotice }] = await Promise.all([
+            import('src/utils/tasks.js'),
+            import('src/services/api/taskAnchorReminder.js'),
+          ]);
+          const notice = buildUnfinishedTaskNotice(await listTasks(getTaskListId()));
+          if (notice) {
+            setMessages(prev => [...prev, createSystemMessage(notice, 'warning')]);
+          }
+        } catch {
+          // Ignore — the notice is a convenience, not part of the turn contract.
+        }
+      }
+
       if (feature('BUDDY') && typeof (globalThis as Record<string, unknown>).fireCompanionObserver === 'function') {
         const _fireCompanionObserver = (globalThis as Record<string, unknown>).fireCompanionObserver as (
           msgs: unknown,

src/services/api/__tests__/taskAnchorReminder.test.ts

@@ -0,0 +1,129 @@
+import { describe, expect, test } from 'bun:test'
+import type { Task } from '../../../utils/tasks.js'
+import {
+  buildTaskAnchorReminder,
+  buildUnfinishedTaskNotice,
+  isAnchorlessNudge,
+} from '../taskAnchorReminder.js'
+
+function task(partial: Partial<Task> & Pick<Task, 'id' | 'status'>): Task {
+  return {
+    subject: `Task ${partial.id}`,
+    description: '',
+    blocks: [],
+    blockedBy: [],
+    ...partial,
+  }
+}
+
+describe('isAnchorlessNudge', () => {
+  test('matches short Chinese keep-going nudges', () => {
+    expect(isAnchorlessNudge('继续执行后续的工作')).toBe(true)
+    expect(isAnchorlessNudge('继续完成当前任务')).toBe(true)
+    expect(isAnchorlessNudge('自动执行后续的所有流程')).toBe(true)
+    expect(isAnchorlessNudge('接着做')).toBe(true)
+  })
+
+  test('matches short English keep-going nudges', () => {
+    expect(isAnchorlessNudge('continue')).toBe(true)
+    expect(isAnchorlessNudge('keep going')).toBe(true)
+    expect(isAnchorlessNudge('go on please')).toBe(true)
+  })
+
+  test('does not match empty or whitespace', () => {
+    expect(isAnchorlessNudge('')).toBe(false)
+    expect(isAnchorlessNudge('   ')).toBe(false)
+  })
+
+  test('does not match long messages that merely contain a nudge word', () => {
+    expect(
+      isAnchorlessNudge(
+        '继续用状态机方案重构 REPL 的输入处理模块，并补齐对应的单元测试',
+      ),
+    ).toBe(false)
+  })
+
+  test('does not match substantive requests without nudge words', () => {
+    expect(isAnchorlessNudge('给我看下 query.ts 的结构')).toBe(false)
+    expect(isAnchorlessNudge('fix the login bug')).toBe(false)
+  })
+})
+
+describe('buildTaskAnchorReminder', () => {
+  test('returns null when there are no unfinished tasks', () => {
+    expect(buildTaskAnchorReminder([])).toBeNull()
+    expect(
+      buildTaskAnchorReminder([
+        task({ id: '1', status: 'completed' }),
+        task({ id: '2', status: 'completed' }),
+      ]),
+    ).toBeNull()
+  })
+
+  test('lists only unfinished tasks, in_progress before pending', () => {
+    const reminder = buildTaskAnchorReminder([
+      task({ id: '1', status: 'completed', subject: 'done' }),
+      task({ id: '2', status: 'pending', subject: 'second' }),
+      task({ id: '3', status: 'in_progress', subject: 'third' }),
+    ])
+    expect(reminder).not.toBeNull()
+    const body = reminder!
+    expect(body).toContain('2 unfinished task(s)')
+    // in_progress (#3) must appear before pending (#2)
+    expect(body.indexOf('#3 [in_progress]')).toBeLessThan(
+      body.indexOf('#2 [pending]'),
+    )
+    expect(body).not.toContain('#1')
+    expect(body).toContain('<system-reminder>')
+    expect(body).toContain('</system-reminder>')
+  })
+
+  test('orders same-status tasks by numeric id', () => {
+    const reminder = buildTaskAnchorReminder([
+      task({ id: '10', status: 'pending', subject: 'ten' }),
+      task({ id: '2', status: 'pending', subject: 'two' }),
+    ])!
+    expect(reminder.indexOf('#2 ')).toBeLessThan(reminder.indexOf('#10 '))
+  })
+
+  test('caps the list and reports overflow', () => {
+    const many: Task[] = Array.from({ length: 25 }, (_, i) =>
+      task({ id: String(i + 1), status: 'pending' }),
+    )
+    const reminder = buildTaskAnchorReminder(many)!
+    expect(reminder).toContain('25 unfinished task(s)')
+    expect(reminder).toContain('…and 5 more')
+  })
+})
+
+describe('buildUnfinishedTaskNotice', () => {
+  test('returns null when no task is in_progress', () => {
+    expect(buildUnfinishedTaskNotice([])).toBeNull()
+    expect(
+      buildUnfinishedTaskNotice([
+        task({ id: '1', status: 'pending' }),
+        task({ id: '2', status: 'completed' }),
+      ]),
+    ).toBeNull()
+  })
+
+  test('surfaces in_progress task names and pending count', () => {
+    const notice = buildUnfinishedTaskNotice([
+      task({ id: '1', status: 'in_progress', subject: '写模块' }),
+      task({ id: '2', status: 'pending' }),
+      task({ id: '3', status: 'pending' }),
+      task({ id: '4', status: 'completed' }),
+    ])!
+    expect(notice).toContain('#1 写模块')
+    expect(notice).toContain('2 个待办')
+  })
+
+  test('collapses overflow when more than three in_progress tasks', () => {
+    const notice = buildUnfinishedTaskNotice(
+      Array.from({ length: 5 }, (_, i) =>
+        task({ id: String(i + 1), status: 'in_progress' }),
+      ),
+    )!
+    expect(notice).toContain('等 5 个')
+  })
+})

src/services/api/claude.ts

@@ -58,6 +58,10 @@ import {
   toolToAPISchema,
 } from '../../utils/api.js'
 import { getOauthAccountInfo } from '../../utils/auth.js'
+import {
+  buildTaskAnchorReminder,
+  isAnchorlessNudge,
+} from './taskAnchorReminder.js'
 import {
   getBedrockExtraBodyParamsBetas,
   getMergedBetas,
@@ -77,6 +81,7 @@ import {
   createAssistantAPIErrorMessage,
   createUserMessage,
   ensureToolResultPairing,
+  getUserMessageText,
   normalizeContentFromAPI,
   normalizeMessagesForAPI,
   stripAdvisorBlocks,
@@ -1337,6 +1342,36 @@ async function* queryModel(
     API_MAX_MEDIA_PER_REQUEST,
   )
 
+  // ── Long-task anchor re-injection ──
+  // When the user's latest message is a short anchorless nudge ("继续"/"keep
+  // going") and the task list still has unfinished items, re-surface them once
+  // for this request. This fires only in that exact situation (short nudge is
+  // the LAST message, which is only true at turn start — during tool loops the
+  // last message is a tool_result), so there is no per-turn token cost. Mirrors
+  // the ephemeral, non-persisted isMeta injection used for deferred tools below.
+  {
+    const lastMessage = messagesForAPI.at(-1)
+    const lastText = lastMessage ? getUserMessageText(lastMessage) : null
+    if (lastText && isAnchorlessNudge(lastText)) {
+      try {
+        const { listTasks, getTaskListId } = await import(
+          '../../utils/tasks.js'
+        )
+        const reminder = buildTaskAnchorReminder(
+          await listTasks(getTaskListId()),
+        )
+        if (reminder) {
+          messagesForAPI = [
+            ...messagesForAPI,
+            createUserMessage({ content: reminder, isMeta: true }),
+          ]
+        }
+      } catch {
+        // Best-effort anchor: task read failures must never block the request.
+      }
+    }
+  }
+
   // OpenAI-compatible provider: delegate to the OpenAI adapter layer
   // after shared preprocessing (message normalization, tool filtering,
   // media stripping) but before Anthropic-specific logic (betas, thinking, caching).

src/services/api/taskAnchorReminder.ts

@@ -0,0 +1,95 @@
+import type { Task } from '../../utils/tasks.js'
+
+// Short, generic "keep going" nudges that carry no task anchor. In a long
+// session these dilute the task anchor and the model drifts off the task
+// (see the long-session drift investigation, 2026-07-23). When one arrives and
+// the task list still has unfinished items, we re-surface them once — only in
+// this exact situation, so there is no per-turn token cost.
+const ANCHORLESS_NUDGE_PATTERN =
+  /(继续|接着|后续|往下|完成剩余|自动执行|自动跑|接着做|keep going|carry on|go on|continue|proceed|next step|move on)/i
+
+// Guard against false positives on substantive messages that merely contain a
+// nudge word (e.g. "继续用 X 方案重构 Y 模块…"). Real anchorless nudges are short
+// — the ones seen in the investigation were all ≤12 CJK chars ("继续执行后续的工作").
+const MAX_NUDGE_CHARS = 20
+
+/**
+ * True when `text` is a short "keep going" style nudge that carries no specific
+ * task anchor. Long messages never match, even if they contain a nudge word.
+ */
+export function isAnchorlessNudge(text: string): boolean {
+  const trimmed = text.trim()
+  if (!trimmed || trimmed.length > MAX_NUDGE_CHARS) {
+    return false
+  }
+  return ANCHORLESS_NUDGE_PATTERN.test(trimmed)
+}
+
+// Cap the injected list so a large backlog can't balloon the reminder.
+const MAX_TASKS_IN_REMINDER = 20
+
+const STATUS_ORDER: Record<string, number> = {
+  in_progress: 0,
+  pending: 1,
+}
+
+/**
+ * Builds a `<system-reminder>` re-surfacing the unfinished tasks, or null when
+ * there are none. in_progress tasks come first, then pending, ordered by id.
+ */
+export function buildTaskAnchorReminder(tasks: Task[]): string | null {
+  const unfinished = tasks.filter(t => t.status !== 'completed')
+  if (unfinished.length === 0) {
+    return null
+  }
+
+  const sorted = [...unfinished].sort((a, b) => {
+    const byStatus =
+      (STATUS_ORDER[a.status] ?? 2) - (STATUS_ORDER[b.status] ?? 2)
+    if (byStatus !== 0) {
+      return byStatus
+    }
+    return Number(a.id) - Number(b.id)
+  })
+
+  const shown = sorted.slice(0, MAX_TASKS_IN_REMINDER)
+  const lines = shown.map(t => `- #${t.id} [${t.status}] ${t.subject}`)
+  const overflow = sorted.length - shown.length
+  if (overflow > 0) {
+    lines.push(`- …and ${overflow} more`)
+  }
+
+  return [
+    '<system-reminder>',
+    `You still have ${unfinished.length} unfinished task(s) in the current task list. The user's last message was a short "keep going" nudge without a specific anchor. Re-align to these tasks and continue the highest-priority unfinished one. Do not end your turn until the tasks are done or you genuinely need user input:`,
+    ...lines,
+    'Use TaskUpdate to mark progress as you go. This reminder is generated by the client, not sent by the user.',
+    '</system-reminder>',
+  ].join('\n')
+}
+
+// How many in_progress task names to spell out in the local notice.
+const MAX_NOTICE_TASK_NAMES = 3
+
+/**
+ * Builds a display-only, user-facing notice for when a turn ends naturally while
+ * tasks are still in_progress — a strong signal the model stopped mid-work. Only
+ * in_progress tasks trigger it (a pending backlog the user is pacing does not).
+ * Returns null when there is nothing worth surfacing. This text is shown in the
+ * REPL and never sent to the model (zero token cost).
+ */
+export function buildUnfinishedTaskNotice(tasks: Task[]): string | null {
+  const inProgress = tasks.filter(t => t.status === 'in_progress')
+  if (inProgress.length === 0) {
+    return null
+  }
+  const pendingCount = tasks.filter(t => t.status === 'pending').length
+  const names = inProgress
+    .slice(0, MAX_NOTICE_TASK_NAMES)
+    .map(t => `#${t.id} ${t.subject}`)
+    .join('、')
+  const overflow = inProgress.length - MAX_NOTICE_TASK_NAMES
+  const namesSuffix = overflow > 0 ? ` 等 ${inProgress.length} 个` : ''
+  const pendingSuffix = pendingCount > 0 ? `，另有 ${pendingCount} 个待办` : ''
+  return `还有进行中的任务未完成：${names}${namesSuffix}${pendingSuffix}。可直接回车继续，或用「按计划继续 Task #N」这类带锚点的话催促，避免长任务跑偏。`
+}