follow-up: compact injected recall history with stable markers

[Qiyuanqiii]

关联 Issue

Refs #120

定位说明

根据分流建议，本 PR 不再作为 #120 的主修复。#120 的运行时提示缓存/注入模式主线应由 #375 等运行时范围 PR 处理。

本 PR 现在收窄为一个可能的后续补充：只处理已经进入 session history 的 <relevant-memories> 注入块，将其压缩为稳定 marker，避免历史中保留整段过期 recall 内容。

本 PR 做了什么

1. 新增 recall history compaction 工具：

   • 将历史中的 <relevant-memories>...</relevant-memories> 压缩为：

     <memory-omitted reason="prevent_context_bloat" />

   • 保留“曾经注入过 memory”的审计痕迹。
   • 移除 turn-specific 的动态 recall 内容。

2. 在 before_message_write 中压缩即将写入历史的注入块：

   • 当前轮 LLM 已经看过完整 recall。
   • 写入 session history 时只保留稳定 marker。

3. 在 before_prompt_build 中增加历史兼容处理：

   • 对已有历史中的 <relevant-memories> 再做一次压缩。
   • 用于覆盖旧 session 或某些 host path 中已进入 event.messages 的注入内容。

4. 新增文档：

   • docs/RECALL-HISTORY-COMPACTION.md
   • 明确说明本 PR 是 narrow follow-up，不替代 runtime-side prompt-cache fix。

5. 新增测试：

   • string message 中 memory block 压缩；
   • multimodal text part 中 memory block 压缩；
   • 不改变 unrelated system/assistant messages；
   • 不同 recalled-memory 历史压缩为相同 marker 形式；
   • 无 injected memory 时保持原消息对象不变。

非目标

• 不改变默认 recall injection mode。
• 不做 system message 去重或重排。
• 不做 provider-specific cache-hit 声明。
• 不替代 fix(recall): stabilize prompt-cache memory injection #375 / runtime-side 的提示缓存主修复。

验证

npm.cmd test -- src/utils/memory-injection-cache.test.ts
npm.cmd test
npm.cmd run build
git diff --check

结果：

• targeted test：1 file，5 tests，passed
• full test：5 files，72 tests，passed
• build：passed
• git diff --check：passed

截图

[YOMXXX]

Triage note: #375 is now the canonical scoped runtime mitigation for #120, with #188/#335 already covering related visibility/test-only pieces.

This PR overlaps on prompt-cache hygiene by compacting historical <relevant-memories> blocks into a stable marker and deduping repeated system messages. That may still be useful as a follow-up, but it should be rebased after #375/#188 and scoped to the incremental history-compaction behavior only.

Recommendation: do not merge this as the primary #120 fix. Re-scope it as a focused follow-up that proves marker-based compaction is preferable to the existing default cleanup behavior, and keep the provider-comparison docs separate if needed.

[Qiyuanqiii]

分流说明：#375 现在是 #120 的规范范围运行时缓解，#188/#335 已经涵盖了相关的可见性/仅测试部分。

这种PR在提示缓存净化上有重叠，通过将历史块压缩为稳定标记并对重复的系统消息进行重复处理。这仍可能作为后续有用，但应在 #375/#188 之后重新基于，并仅限于增量历史压缩行为。<relevant-memories>

建议：不要把它合并为主要的#120修正。将其重新定义为一个聚焦的后续，证明基于标记的压缩比现有默认清理行为更优，并在需要时保持提供者比较文档分开。

感谢大佬您的分流说明，我理解的大佬您的意思是这样的：#375 更适合作为 #120 的运行时范围主修复，而 #439 不应该继续声称覆盖 provider/prompt-cache 主线。所以我已经根据建议重新收窄了 #439 的作用范围：现在它只保留“基于 marker 的历史压缩”这一点，作为可能的后续补充。

以下是具体调整：

• 移除了 system message 去重逻辑，避免和更广泛的运行时/提示处理混在一起；
• 删除了 DeepSeek/MiMo provider 对比和 provider cache-hit 声明；
• 将文档改为 docs/RECALL-HISTORY-COMPACTION.md，明确写明这是 narrow follow-up，不替代 fix(recall): stabilize prompt-cache memory injection #375 / runtime-side fix；
• 现在只处理已经进入 session history 的 <relevant-memories>，将其压缩为 <memory-omitted reason="prevent_context_bloat" />；
• 保留 before_message_write 和 before_prompt_build 两道压缩，用于新写入历史和旧历史兼容。

新的提交是 729ec25。如果大佬您认为这个 marker-based history compaction 仍然应该等 #375 合并后再重新基于它处理，我也可以继续调整或关闭后重开

Thank you for the triage clarification. My understanding of your point is as follows: #375 is a better fit as the scoped runtime-side primary fix for #120, while #439 should no longer claim to cover the provider / prompt-cache mainline. Based on your recommendation, I have narrowed the scope of #439 accordingly: it now only keeps the “marker-based history compaction” part as a possible follow-up enhancement.

The specific changes are:

• Removed the system message deduplication logic to avoid mixing this PR with broader runtime / prompt handling behavior;
• Removed the DeepSeek / MiMo provider comparison and provider cache-hit claims;
• Renamed the documentation to docs/RECALL-HISTORY-COMPACTION.md, explicitly stating that this is a narrow follow-up and does not replace fix(recall): stabilize prompt-cache memory injection #375 or the runtime-side fix;
• Now only handles <relevant-memories> blocks that have already entered session history, compacting them into <memory-omitted reason="prevent_context_bloat" />;
• Kept both before_message_write and before_prompt_build compaction paths, covering newly written history as well as compatibility with existing history.

The new commit is 729ec25. If the maintainers think this marker-based history compaction should still wait until #375 is merged and then be rebased on top of it, I can continue adjusting it, or close this PR and reopen a smaller one later.

[Qiyuanqiii]

分流说明：#375 现在是 #120 的规范范围运行时缓解，#188/#335 已经涵盖了相关的可见性/仅测试部分。

这种PR在提示缓存净化上有重叠，通过将历史块压缩为稳定标记并对重复的系统消息进行重复处理。这仍可能作为后续有用，但应在 #375/#188 之后重新基于，并仅限于增量历史压缩行为。<relevant-memories>

建议：不要把它合并为主要的#120修正。将其重新定义为一个聚焦的后续，证明基于标记的压缩比现有默认清理行为更优，并在需要时保持提供者比较文档分开。

大佬大佬，能不能麻烦您有空再帮忙看下这个收窄后的方向是否符合预期，如果您仍然觉得应该继续拆分，我也可以继续调整。

[Maxwell-Code07]

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