[ranxianglei]

是什么 / What

Fork/resume 采纳(applyForkAdoption)搬 blocks、refs、token snapshot 等,但不搬 Anthropic 缓存断点账本(session.metadata.anthropicCacheMarkIds)。新采纳的会话首轮 anthropic 请求只能打一个尾部断点:早期前缀在子会话侧从未申请过缓存,写阶梯从空开始重建(#5519)。观测:fork 首轮 8.07MB 请求与父会话末轮字节公共前缀仅 2,552 字节(0.03%),第 2 轮起才回到 ~90% 命中。

修法 / Fix

• applyForkAdoption 武装一次性标志 metadata.cacheMarkLadderInitPending(四条采纳路径——匿名 fork、identified resume、derived fork、boot reconcile——都汇聚于此,一处覆盖全部)。
• 子会话首次 anthropic-owned 布点时按位置铺 25% / 50% / 尾部三点(仅在无存活 marks 且 lastIndex>=3 时);标志无条件消费。此后走原 [Bug] Anthropic lane never emits cache_control breakpoints — prompt cache can only ever cover the system head (~11K), the whole history re-bills at full price every request #1637 粘性动态(marks 到上限即冻结,直到折叠退役被覆盖者)。
• 刻意不逐字继承父会话 mark ids:父侧位置在子会话视图里是陈旧的,且 3 个继承 marks 会填满 MESSAGE_MARK_CAP=3、阻塞子会话自己的尾部 push——第 2 轮命中深度反而比现状更差(issue 建议 1 的字面实现是负优化,已在 issue 线程说明)。

行为变更披露(old → new)

• fork/resume 首轮 anthropic 请求:消息断点 1 个(仅尾部)→ 最多 3 个(1/4、1/2、尾部)。有意变更,issue 所诉;稳态会话字节级不变(标志只在采纳瞬间武装,一次性消费)。
• 配置面(config surface):无变更——新增字段是内部 metadata 标志,不是配置项,不进入 config/env/CLI。
• kernel-guard:不涉及——纯 host 侧(src/loop/cache-control.ts + src/fork-adoption.ts),零 kernel/ 触碰。

测试 / Tests

• 新增 tests/issue5519-fork-cache-mark-inherit.test.ts(8 例:非 fork 现状钉死、标志武装且不复制父 marks、种子形状、次轮冻结、折叠退役后补位、短历史回退单尾、已有存活 mark 不重排、ephemeral 尾巴不入点)。
• tests/fork-adoption-plan.test.ts fixture 补上 Session 类型必需的 metadata: {}(既有缺陷:缺它 applyForkAdoption 会崩,与本修复同路径)。
• 已知无关红:tests/fork-adoption-wires.test.ts 有 2 条在干净 master fad9805bc 与干净 ci-fixes 821dbc04b 上同样失败(fixture 前置断言 "must have a folded block",在任何采纳代码运行前),clean worktree 双证;若 CI 分片以此签名红,属继承性失败,已按政策走 CI Control Center: Centralized CI Failure Handling & Status Sync (Comment all CI issues here; do not open new issues) | CI 总控: CI 失败集中处理与状态同步(所有 CI 问题在此评论, 勿开新 issue) #4599。

Closes #5519

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Branch: 2026-11-02_fork-cache-mark-ladder-init (b963644)

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[ranxianglei]

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查重: 不重复。按失败签名(fork 采纳 × Anthropic 缓存断点继承 / anthropicCacheMarkIds)检索 open+closed issue 与 PR,唯一相关项是 #1349(fork 采纳携带父会话 CCR content-store 条目)——同一采纳路径但不同账本、不同机制(content store vs 缓存断点账本),非重复。

标签: bug, dsh, scope/wiring, p2(理由:fork 首轮缓存命中崩塌是成本/性能缺陷,可用不卸载、第 2 轮起自愈回 ~90% → p2;报告车道为 dsh;改动面在 wire 层 cache-control + fork-adoption,归协议接线域)。

开始对 PR #5525 做独立审核(分支 2026-11-02_fork-cache-mark-ladder-init @ 3e52c6d,base master):原 issue 方向核查 → 既有行为回归清点 → 代码与测试有效性 → CI 状态,结论按结构化八问给出。

[ranxianglei]

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[bot] 🏷
(ai: vllm-qwen/qwen3.8-27b)

PR #5525 独立复审结论:可合。

八问

1. 是什么问题:fork/resume 采纳搬了 blocks/refs/token 快照,没搬 Anthropic 缓存断点账本(anthropicCacheMarkIds),子会话首轮只能打一个尾部断点,首轮缓存命中塌掉([bug] Fork first-turn cache breakpoints degrade to a single tail marker (anthropicCacheMarkIds not inherited) | [bug] fork 首轮缓存断点退化为单个尾部标记（anthropicCacheMarkIds 未继承） #5519 实测与父会话末轮公共前缀仅 0.03%)。
2. 什么原因导致的:applyForkAdoption 的拷贝清单漏了断点账本,写阶梯从空重建;而单尾 push 的设计本身无法为已稳定的早期前缀补打断点——是「采纳丢账本」+「阶梯只能增量长」两个机制叠加。
3. 影响范围与严重程度:所有 anthropic-owned 的 fork/resume 会话(主要 dsh desktop fork 场景);确定性成本问题(采纳后第 1 轮多付前缀钱,第 2 轮起恢复 ~90%),无数据丢失、无不可用——p2 定级成立。
4. 怎么修复的:在四条采纳路径的唯一汇聚点武装一次性标志 cacheMarkLadderInitPending,子会话首次 anthropic-owned 布点时按自身稳定区 ¼/½/尾部铺三点(仅在无存活 marks 且 lastIndex>=3);此后回到原 [Bug] Anthropic lane never emits cache_control breakpoints — prompt cache can only ever cover the system head (~11K), the whole history re-bills at full price every request #1637 粘性动态。刻意不逐字继承父侧 mark ids 这个取舍我独立验证后认同:父侧位置在子视图里是陈旧的,且 3 个继承 marks 会填满 MESSAGE_MARK_CAP=3、阻塞子会话自己的尾部 push,反而更差。
5. 是否有回归问题:审过的既有行为——稳态会话字节级不变(标志只在采纳瞬间武装、一次性消费);非 fork 路径不变(有现状钉死测试);client-managed 会话不受影响(抑制发生在调用之前);两种压缩模式走同一 prepare 层、与模式无关;cap 永不超限(seed 从空账本起、≤3 次 push);请求重试幂等(每请求消费一次)。未发现回归。
6. 是否破坏缓存:不破坏——此变更本身就是修复断点账本;稳态命中率不变,fork 首轮命中深度改善。
7. 是否改了设计方向:没有——纯 host 侧 metadata 标志 + 布点策略扩展;零 kernel/ 触碰,wire 形状不变(cache_control 点数本就是协议内变量)。
8. 是否引入新配置:无——内部 metadata 标志,不进 config/env/CLI,与 PR 披露一致。

验证证据(独立重做,未照抄 issue 结论)

• 四条采纳路径(匿名 fork / identified resume / derived fork / boot reconcile)确实全部汇聚到 applyForkAdoption——逐行核过(handle.ts:1535/1661/1737/1789,server.ts:584,fork-adoption.ts:396/453/590),「一处覆盖全部」的说法成立。
• computeAnthropicMessageMarks 全仓唯一调用点在 prepare-anthropic.ts:478;round-2 loop 重建经 [bug] anthropic 线 proxy 模式：压缩回合的 round-2 重建丢失客户端 cache_control，折叠后下一条请求只能命中 system 前缀 #2499 复用同一份 marks。
• 本地定向跑(PR head worktree):新增 8 例 + fixture 3 例共 11 pass 0 fail;既有 tests/anthropic-cache-control.test.ts 8 pass 0 fail;tests/fork-adoption-wires.test.ts 2 条失败在干净 master fad9805 上同签名复现 → 继承性红坐实(fixture 前置断言失败,先于任何采纳代码运行),与本 PR 无关;若 CI 分片以此签名红,按政策走 CI Control Center: Centralized CI Failure Handling & Status Sync (Comment all CI issues here; do not open new issues) | CI 总控: CI 失败集中处理与状态同步(所有 CI 问题在此评论, 勿开新 issue) #4599。
• CI:三层 CI(feat!: remove image pre-compression and the image_full tool (#3266) #3295)下普通 PR 只跑 CORE 矩阵——head 3e52c6d4d 的检查全绿(6 个 gate job,零红项),完整单元套件按设计未在本 PR 上跑;想要全矩阵信号可给 PR 加 ci:full 标签。

顺手小修(独立标注 commit da7d76787,已推到 PR 分支):cache-control.ts 行内注释声称标志「无条件消费」,与实际机制不符——client-managed 或过短的首轮根本到不了消费点,标志会保持武装(安全,因为 seed 是首次出现式布局而非改写已盖章字节,但注释措辞必须改对)。纯注释变更,零行为变化;推送后 CI 将按同一 CORE 范围重跑。

判定:可合。 行为变更披露与 PR 描述一致(fork/resume 首轮消息断点 1→最多 3,有意变更;稳态不变),配置面与 kernel 均未触碰。合并请 owner 操作:#5525

[ranxianglei]

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本 PR 的独立审核已在 floor 6 完成并给出「可合」+ 八问。本次是同任务重触发,我没有照抄 floor 6,而是独立重跑了一遍端到端核查;结论一致,维持可合,且没有新发现。

八问(本轮复核,精简版)

1. 是什么问题:fork/resume 采纳搬了 blocks/refs/token 快照却没搬 Anthropic 缓存断点账本(anthropicCacheMarkIds),子会话首轮只能打一个尾部断点,首轮命中塌掉([bug] Fork first-turn cache breakpoints degrade to a single tail marker (anthropicCacheMarkIds not inherited) | [bug] fork 首轮缓存断点退化为单个尾部标记（anthropicCacheMarkIds 未继承） #5519 实测与父末轮公共前缀 0.03%)。
2. 什么原因:applyForkAdoption 拷贝清单漏了断点账本 + 单尾 push 无法为已稳定的早期前缀补点,两机制叠加。
3. 影响面/严重度:所有 anthropic-owned 的 fork/resume(主 dsh desktop fork);确定性成本问题,第 2 轮起自愈回 ~90%,无数据丢失/不可用 → p2 成立。
4. 怎么修:四条采纳路径唯一汇聚点武装一次性标志 cacheMarkLadderInitPending,子会话首次 anthropic-owned 布点按自身稳定区 ¼/½/尾部铺三点(仅无存活 marks 且 lastIndex>=3),此后回原 [Bug] Anthropic lane never emits cache_control breakpoints — prompt cache can only ever cover the system head (~11K), the whole history re-bills at full price every request #1637 粘性动态。刻意不逐字继承父 marks——独立验证认同(父位置在子视图陈旧,且填满 CAP=3 会阻塞子自身尾 push,反而更差)。
5. 回归:稳态字节级不变(标志只在采纳瞬间武装、一次性消费);非 fork 走原 else 分支不变;client-managed 抑制发生在调用之前、不受影响;两种压缩模式走同一 prepare 层;cap 永不超限(seed 从空账本起 ≤3 push)。未发现回归。
6. 缓存:不破坏——此变更本身就是修断点账本;稳态命中率不变,fork 首轮命中深度改善。
7. 设计方向:没改——纯 host 侧 metadata 标志 + 布点策略扩展;零 kernel/ 触碰,wire 形状不变(cache_control 点数本就是协议内变量)。
8. 新配置:无——内部 metadata 标志,不进 config/env/CLI,与 PR 披露一致。

独立复核证据(自己重做,非转录)

• 四条采纳路径确全汇聚 applyForkAdoption(fork-adoption.ts:396/453/590;derived fork 经 maybeAdoptResume→453),「一处覆盖全部」成立。
• computeAnthropicMessageMarks 唯一调用点 prepare-anthropic.ts:478;client-managed/过短/knob-off 的首轮在到达标志代码之前就 return → 该轮不消费标志,但安全(seed 属首次出现式布局,不是改写已盖章字节;有存活 marks 时 kept.length===0 门再挡一次,绝不重排)。
• createSession(session.ts:1393)恒初始化 metadata → fork-adoption.ts:304 的写入在生产环境不会崩;直接调 applyForkAdoption 的 fixture 仅 2 处,fork-adoption-plan.test.ts 已补 metadata:{},新文件 fakeSession 自带。
• seed ≤3 message marks(+system)= ≤4,且仅 client/tools 均无 cache_control 时才布点 → 不破 Anthropic 4-breakpoint 预算(WC-010)。
• 新增 8 例断言有牙(现状钉死/不复制父 marks/seed 形状/次轮冻结/折叠退役补位/短史回退单尾/已有 mark 不重排/ephemeral 不入点),能抓回归;config 面与 kernel 均未触碰。

状态核对:分支 tip 现为 da7d76787(floor 6 顺手修的注释更正,comment-only,措辞正确——它准确指出 client-managed 首轮根本到不了消费点)。我本地一度对同一处注释产生了重复改动,已丢弃、未推第二份(避免重复提交)。checks(mirror cache):gate/static-gates/mysql-contract 全绿,完整 test 矩阵 in_progress(0 失败);comment-only delta over 已绿的 3e52c6d4d,预期落地即绿。

判定:可合(维持 floor 6)。 无新发现、无新提交。合并请 owner 操作:#5525

协调回报(一行):PR #5525 审核完成——可合,修复 da7d76787 已落分支,待 owner 合并。(注:本次派发未给出独立的评审协调 issue 编号;#4599 为 CI 总控、本 PR 无 CI 失败不适用,故状态记录于本线程。)

[ranxianglei]

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Conflict resolved and pushed — branch 2026-11-02_fork-cache-mark-ladder-init now sits at b963644a40 (was da7d767873, 921 commits behind master). Live verification this run: PR mergeable: true (the dirty/conflict state is gone); mergeable_state: blocked only because fresh check runs are still starting on the new head.

七问 summary

1. What was done this run: merged current origin/master (58a8796224) into the PR branch, resolved the conflict, fixed a related semantic break the textual merge hid, verified locally, pushed (fast-forward, no force-push), and re-verified the remote head.
2. What the blocker actually was: one textual conflict — both sides had inserted different code at the same spot in applyForkAdoption (src/fork-adoption.ts, right before markDirty(session)): master added the # Cache hit collapses to 1–12% for a whole generation, then the very next request returns to 100% — repeated 15× in one day #5608/feat: Support precise timestamps for each message, allowing the model to recognize which messages are outdated and which | feat: 给每个消息支持精确时间,以让模型认识到什么消息是过期的什么是当前的新的 #4313 timestamp-ledger carry (seedTimestampsFromParent + timestampsHighWaterRefSeq) while this PR armed the [bug] Fork first-turn cache breakpoints degrade to a single tail marker (anthropicCacheMarkIds not inherited) | [bug] fork 首轮缓存断点退化为单个尾部标记（anthropicCacheMarkIds 未继承） #5519 cacheMarkLadderInitPending flag. Additionally, master's new tests exposed a semantic conflict git can't detect: four of master's new fixtures call applyForkAdoption (two directly, two via maybeAdoptResume) with child Sessions that have no metadata field, which crashes once the PR's unconditional session.metadata["cacheMarkLadderInitPending"] = true runs.
3. How it was resolved: the textual conflict as a strict union of intent — master's timestamp carries verbatim, then the PR's flag arming (independent fields, no interaction). The fixture break by adding metadata: {} to each affected fixture (tests/fork-adoption-plan.test.ts ×1, tests/resume-miss-timestamp-seed.test.ts ×3) — the exact same defect class this PR already fixed in its own [Bug][plugin] protectedTools 的 BLOCKED 映射导致纯文本 snapshot 返回 409 #2620 fixture. Production sessions always carry metadata (createSession initializes it), so the fixtures were the defective side; zero production-code change beyond what was already reviewed. Labeled commit: b963644a40.
4. Verification evidence (merged head, local targeted runs): typecheck clean; issue5519-fork-cache-mark-inherit + fork-adoption-plan + anthropic-cache-control + resume-miss-timestamp-seed → 34/34 pass; fork-adoption-wires.test.ts keeps exactly its two known inherited-reds with the identical pre-merge signature ('responses parent must have a folded block (got 0)' — fixture precondition failing before any adoption code runs; already documented in the PR body as inherited from clean master fad9805bc). Final PR diff vs current master is minimal: 5 files, +187/−4.
5. Behavior change / regression: none introduced by this resolution — both sides' behaviors are preserved byte-for-byte (the PR's own disclosed change, fork-first-turn breakpoints 1→≤3, is unchanged from the reviewed version). Steady-state sessions untouched; no config surface, no kernel touch, no wire-shape change.
6. Current live state (verified in this run, not from memory): remote head = b963644a40; GitHub reports mergeable: true. The mirror check cache was still serving the stale 2026-11-02 snapshot (old sha) when I looked, so I cannot yet assert the outcome of the new check runs — they will appear on the next mirror poll.
7. Residual risks / next steps: if a full-matrix shard goes red on the fork-adoption-wires signature above, that is the documented inherited failure and belongs under CI coordination issue CI Control Center: Centralized CI Failure Handling & Status Sync (Comment all CI issues here; do not open new issues) | CI 总控: CI 失败集中处理与状态同步(所有 CI 问题在此评论, 勿开新 issue) #4599, not this PR. Otherwise nothing further is expected from me on this branch; merging stays with the owner: [PR] fix: seed the Anthropic cache-breakpoint ladder on fork adoption (#5519) #5525

[ranxianglei]

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Confirming for the record: this run is complete — the full 七问 summary was already posted as the previous comment in this thread (comment id 71320) and is not being repeated here.

State verified live in this run: branch 2026-11-02_fork-cache-mark-ladder-init = b963644a40 (master 58a8796224 merged in, conflict resolved as union of intent + fixture metadata: {} fixes, pushed fast-forward); GitHub reports mergeable: true; local targeted suites 34/34 green, typecheck clean. Nothing further pending from this lane — merging stays with the owner (#5525). If any check shard goes red on the documented inherited fork-adoption-wires signature, that routes to CI coordination issue #4599, not this PR.

[ranxianglei]

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复审(新 head b963644a4)— 结论维持「可合」。 本轮是同一任务在新 head 上的重触发。我先按 merge-base 隔离出本 PR 相对当前 master 的真实增量(merge-base = master tip 58a87962,分支已干净 rebase 到最新 master),避免把 master 吸收进来的大量无关改动误判成io本 PR 的工作。

自上次评审后真正新增的只有 1 个提交:

• b963644a4 test(fork-adoption): give master's new applyForkAdoption fixtures the required metadata field —— 纯测试夹具卫生。rebase 到当前 master 后,master 新增了 4 个调用 applyForkAdoption 的夹具(2 个直接、2 个经 maybeAdoptResume),其 child Session 缺 metadata 字段;而本 PR 让 applyForkAdoption 无条件写 session.metadata.cacheMarkLadderInitPending,故这 4 处夹具需补 metadata:{}。4 处 hunk 全部只加 metadata:{}(各带一句准确 WHY 注释),零生产代码改动。方向正确:生产会话恒由 createSession(session.ts:1393)初始化 metadata,所以缺陷方是夹具——与本 PR 早已修的 fork-adoption-plan.test.ts [Bug][plugin] protectedTools 的 BLOCKED 映射导致纯文本 snapshot 返回 409 #2620 夹具缺口同类。作者本地验证(typecheck 干净、定向套件 34/34、既有 inherited-red 签名不变)与我独立核实的结论一致。

核心修复内容未变(rebase 前后我逐一比对,字节级一致):

• src/fork-adoption.ts:四条采纳路径的唯一汇聚点武装一次性标志 session.metadata["cacheMarkLadderInitPending"]=true(带 WHY 注释)。
• src/loop/cache-control.ts:computeAnthropicMessageMarks 在子会话首次 anthropic-owned 布点时按自身稳定区铺 ¼/½/尾三点(门 kept.length===0 && lastIndex>=3,否则回原单尾 push),并含 da7d767873 已更正的标志消费语义注释。

八问(精简版,详版见 floor 6)

1. 是什么问题:fork/resume 采纳搬了 blocks/refs/token 快照却没搬 Anthropic 缓存断点账本,子会话首轮只能打一个尾部断点,首轮命中塌掉([bug] Fork first-turn cache breakpoints degrade to a single tail marker (anthropicCacheMarkIds not inherited) | [bug] fork 首轮缓存断点退化为单个尾部标记（anthropicCacheMarkIds 未继承） #5519 实测与父末轮公共前缀 0.03%)。
2. 什么原因:applyForkAdoption 拷贝清单漏了断点账本,叠加单尾 push 无法为已稳定的早期前缀补点。
3. 影响面/严重度:所有 anthropic-owned 的 fork/resume(主 dsh desktop fork);确定性成本问题,第 2 轮起自愈回 ~90%,无数据丢失/不可用 → p2 成立。
4. 怎么修:唯一汇聚点武装一次性标志,子会话首轮按自身稳定区铺三点,此后回原粘性累积动态;刻意不逐字继承父 marks(父位置在子视图陈旧,且填满 CAP=3 会阻塞子自身尾 push)。
5. 回归:稳态字节级不变(标志只在采纳瞬间武装、一次性消费);非 fork 走原 else 分支不变;client-managed 抑制发生在调用之前、不受影响;cap 永不超限(seed 从空账本起 ≤3 push)。未发现回归。
6. 缓存:不破坏——此变更本身就是修断点账本;稳态命中率不变,fork 首轮命中深度改善。
7. 设计方向:没改——纯 host 侧 metadata 标志 + 布点策略扩展;隔离增量里零 kernel/ 触碰,wire 形状不变(cache_control 点数本就是协议内变量)。
8. 新配置:无——内部 metadata 标志,不进 config/env/CLI。

CI(mirror cache @ b963644a4):{total:30, failed:0, pending:0} —— 全部完成、零失败。完整 test 矩阵(ubuntu/windows × node22/24 各 shard)+ gate/static-gates/mysql-contract 全绿;重 e2e 车道按仓规 gated-skip(canary/env 门控,与上轮一致)。mergeable_state:blocked 仅因等待 review,CI 本身已全绿。

判定:可合(APPROVE)。 无新发现、无遗留项(NO OPEN ENDS)、未触碰 kernel/ 故无需决策升级。合并请 owner 操作:#5525

协调回报(一行):PR #5525 新 head b963644a4(rebase 到最新 master + 1 个机械性测试夹具修复)审核完成——可合,CI 全绿,待 owner 合并。(注:本次派发未给出独立的评审协调 issue 编号;#4599 为 CI 总控、本 PR 无 CI 失败不适用,故状态记录于本线程。)

[ranxianglei]

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Verified live this run: there is no conflict to resolve and no red CI to fix — the branch is green and merge-ready. The blocker flag arrived after master moved again, but the authoritative sources say otherwise:

七问 summary

1. What was done this run: fetched both heads, read the live PR state from GitHub, read the mirror check cache for the pushed head, diffed the 5 new master commits against the PR's file set, and ran a local git merge-tree dry-run of branch×master. No changes were needed, so nothing was pushed (branch head unchanged at b963644a40).
2. What the "dirty" state actually was: staleness, not a real conflict. Master advanced 5 commits (58a8796224 → 33104b1f95, the compressAtFoldPoint removal work Remove the compressAtFoldPoint feature — it reorders resent history and caused an authorship-misattribution incident in a live session #6132/[PR] remove: the experimental compressAtFoldPoint feature — fold-point relocation (v1 #5471 + unreleased v2 #5949), #6132 #6150) after last night's conflict-resolution push; GitHub's async mergeability recompute had not settled when the blocker fired. Live now: mergeable: true, mergeable_state: behind — clean, just stale. The local git merge-tree --write-tree dry-run confirms a byte-clean merge (exit 0, zero conflict paths).
3. Why no sync merge was done: the 5 new master commits touch 41 files with zero overlap with the PR's 5 files, and neither src/fork-adoption.ts nor src/loop/cache-control.ts references compressAtFoldPoint — no semantic interaction of any kind. A gratuitous sync merge would burn a full test-matrix re-run to prove what the dry-run merge already proves; it would also add a merge commit that widens future conflict surface. If the owner prefers an up-to-date base before merging, say so and I'll do one clean sync pass.
4. CI evidence (mirror cache snapshot taken against exactly this head b963644a40): every executed check success — all test shards (ubuntu/windows × node 22/24), static-gates (both platforms), mysql-contract, gate; red-signal skipped; the e2e lanes skipped by their env-var gates by design. No shard went red, including the previously-watched fork-adoption-wires signature — nothing routes to CI Control Center: Centralized CI Failure Handling & Status Sync (Comment all CI issues here; do not open new issues) | CI 总控: CI 失败集中处理与状态同步(所有 CI 问题在此评论, 勿开新 issue) #4599 this run.
5. Behavior change / regression: none introduced this run (zero commits). Last night's resolution remains as disclosed there: union-of-intent in applyForkAdoption + fixture-only metadata: {} additions, no production-code change beyond the reviewed [bug] Fork first-turn cache breakpoints degrade to a single tail marker (anthropicCacheMarkIds not inherited) | [bug] fork 首轮缓存断点退化为单个尾部标记（anthropicCacheMarkIds 未继承） #5519 diff.
6. Current live state: branch = b963644a40 (verified via fetch, remote head matches); GitHub = open, mergeable: true, state behind (5 commits); checks green on this head per the cache above.
7. Next steps: nothing pending from this lane — the PR is ready for the owner to merge whenever: [PR] fix: seed the Anthropic cache-breakpoint ladder on fork adoption (#5519) #5525. If a future master move produces a real textual or semantic conflict, the same lane will resolve it the same way (union of intent, targeted verification, labeled commits).