feat(pi-hermes-memory): 接入持久记忆扩展并移除 Hippo

用仓库内 pi-hermes-memory 替换 hippo-memory-pi，清理 Hippo 在组合包中的
全部注入点。

移除 Hippo：
- 删除 hippo-memory-pi/ 与 config/hippo-memory-version。
- extensions/plugin-init.ts 只保留 CodeGraph 初始化目标与预检。
- install.sh / update.sh / uninstall.sh 移除 Hippo CLI 的安装、升级、卸载
  与版本校验逻辑；uninstall.sh 同时删除仅服务于该提示的死代码 ask_yes_no。
- 删除 tests/hippo-extension.test.ts 与 tests/hippo-scripts.test.ts。
- tests/extension-load.test.ts 反转“不得加载 Hermes”的断言为必须加载，
  并断言其排在 pi-compaction 之前。

接入 pi-hermes-memory：
- package.json 增加 file:./pi-hermes-memory 依赖、files 条目与加载入口；
  加载顺序位于 pi-compaction 之前，否则 flushOnCompact 会被 pi-compaction
  的 { cancel: true } 静默跳过。
- 六个记忆工具在 Tool Search 中常驻：memory_search 与 session_search 连同
  context_tree_query 归入 memory-recall，memory_add / memory_replace /
  memory_remove / skill_manage 归入 memory-management。常驻是必需的——注入
  的 memory policy 会在普通工作中指示模型调用它们，schema 不可见会让模型
  静默放弃而不是去 tool_search，同时常驻也保持请求前缀缓存稳定。
- bundleDefaultsVersion 由 2 升到 3；migrate-tool-search-settings.mjs 新增
  上一版快照到当前版本的迁移路径，仍只迁移完整匹配的默认快照并保留自定义
  配置。
- config/pi-permission-policy.jsonc 为六个工具设置 allow：它们只写扩展自己的
  agent 目录数据、不触碰工作区，且 memory_search 每轮都可能被调用，落入
  默认 ask 会产生每轮 AutoReview 往返。

依赖：
- pi-hermes-memory 的 devDependencies 由上游 ^0.80.2 等范围改为与根包一致的
  精确版本。上游范围与根包 0.84.2 不兼容，会让 npm 在本目录嵌套安装第二套
  Pi runtime（实测 229 MB），违反“不得在组合包内再安装一套 Pi runtime”的
  纪律。
- 根 allowScripts 保持只有 better-sqlite3@12.11.1。hermes 的
  better-sqlite3@13 运行时 dlopen 的是包内 N-API 预编译二进制
  prebuilds/<platform>.node，npm 因 binding.gyp 推断出的 node-gyp rebuild
  无需执行；实测删除 build/ 目录后仍正常工作。

文档：AGENTS.md 与 README.md 改写记忆章节，新增 pi-hermes-memory 开发约定，
替换文末的 Hippo 项目记忆块。

验证：根 12 个测试文件、pi-tool-search 的 typecheck/test/build、
pi-permission-system 的 typecheck/2569 测试、pi-hermes-memory 自带的 59 个
测试文件全部通过；隔离 Pi 环境联合加载无错误并生成 bundleDefaultsVersion 3；
npm install 幂等；迁移 helper 对 v2 快照迁移、对自定义配置保留。

pi-tool-search/extensions/bundle-groups.ts

@@ -141,21 +141,21 @@ export const BUNDLE_GROUP_DEFINITIONS: BundleGroupDefinition[] = [
   },
   {
     id: "memory-recall",
-    title: "Official Hippo memory recall",
-    summary: "Recall project memories, inspect Hippo status/context, or recover pruned tool-call output.",
-    useWhen: ["Past project lessons, errors, decisions, or condensed outputs may answer the question"],
-    avoidWhen: ["The required evidence is already in the current visible context"],
-    keywords: ["memory", "recall", "context", "status", "recover", "记忆", "召回", "恢复输出"],
-    tools: ["hippo_recall", "hippo_context", "hippo_status", "context_tree_query"],
+    title: "Persistent memory recall",
+    summary: "Search durable user, global, project, and failure memories, search indexed past conversations, or recover pruned tool-call output.",
+    useWhen: ["The task may depend on durable context from previous sessions: preferences, project conventions, prior decisions, known failures, corrections, or condensed outputs"],
+    avoidWhen: ["The required evidence is already in the current visible context, or the question is a generic one-off that durable memory would not help"],
+    keywords: ["memory", "recall", "search", "session", "history", "recover", "记忆", "召回", "检索", "历史会话", "恢复输出"],
+    tools: ["memory_search", "session_search", "context_tree_query"],
   },
   {
     id: "memory-management",
-    title: "Official Hippo memory management",
-    summary: "Store durable project lessons or report whether recalled Hippo memories were useful.",
-    useWhen: ["A non-obvious project lesson, error, or decision should persist, or recalled memories need feedback"],
-    avoidWhen: ["The information is temporary task progress or derivable from the repository"],
-    keywords: ["remember", "outcome", "lesson", "error", "记住", "反馈", "项目经验"],
-    tools: ["hippo_remember", "hippo_outcome"],
+    title: "Persistent memory management",
+    summary: "Save, update, or remove durable memories, and create or maintain reusable procedural skills.",
+    useWhen: ["A durable fact, preference, convention, correction, or non-obvious reusable procedure should persist across sessions"],
+    avoidWhen: ["The information is temporary task progress, derivable from the repository, or a one-off detail that would add noise"],
+    keywords: ["remember", "save", "replace", "remove", "skill", "procedure", "记住", "保存", "修改记忆", "技能", "流程"],
+    tools: ["memory_add", "memory_replace", "memory_remove", "skill_manage"],
   },
   {
     id: "subagents",

pi-tool-search/extensions/config.ts

@@ -20,6 +20,12 @@ export const BUNDLE_TOOL_SEARCH_DEFAULTS = {
     "ctx_execute",
     "ctx_execute_file",
     "ctx_batch_execute",
+    "memory_search",
+    "session_search",
+    "memory_add",
+    "memory_replace",
+    "memory_remove",
+    "skill_manage",
   ],
   showToolSearchFooterStatus: false,
   maxActiveGroups: 5,
@@ -28,7 +34,7 @@ export const BUNDLE_TOOL_SEARCH_DEFAULTS = {
   groupOverrides: {},
 } as const;
 
-export const BUNDLE_TOOL_SEARCH_DEFAULTS_VERSION = 2;
+export const BUNDLE_TOOL_SEARCH_DEFAULTS_VERSION = 3;
 
 export interface ToolSearchConfig {
   alwaysEnabled: string[];