feat(pi-overflow): 新增统一的新工具结果展示截断扩展

此前截断分散在多层且互相冲突：Pi bash 保留尾部 50KB，RTK 兜底截断又只留
开头 12000 字符（砍掉报错与完整输出路径），pi-chrome 截开头 30K，web_fetch
各 provider 不一致。新扩展统一负责"新结果给模型看多少"：
- capture.ts 最先加载暂存原文，index.ts 最后加载（system-prompt 之前）
- 超过 24K 字符时原文落盘 <agentDir>/my-pi/pi-overflow/（700/600、原子写），
  优先取 bash fullOutputPath 完整文件；模型看到 头 + 中段信号行 + 尾 的有界
  视图，行号基于落盘原文、结尾永远可见
- overflow_query：按 id 正则搜索、行区间、jsonPath 只读查询，id 校验防穿越
- 收编：RTK truncate 默认关闭、删除 pi-chrome truncateText、web_fetch 默认
  每页 20000（上限 100000）、web_search max_results 限定 1–20
- pi-compaction 遮蔽带 details.overflow.id 的结果时在占位符提示 overflow_query
- 登记 tools.jsonc / routing / 权限 allow / tool-search 常驻与分组

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

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

@@ -124,11 +124,11 @@ export const BUNDLE_GROUP_DEFINITIONS: BundleGroupDefinition[] = [
   {
     id: "memory-recall",
     title: "Persistent memory recall",
-    summary: "Search durable user, global, project, and failure memories, search indexed past conversations, or recover pruned tool-call output.",
+    summary: "Search durable user, global, project, and failure memories, search indexed past conversations, or recover pruned or overflow-stored 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"],
+    keywords: ["memory", "recall", "search", "session", "history", "recover", "overflow", "记忆", "召回", "检索", "历史会话", "恢复输出"],
+    tools: ["memory_search", "session_search", "context_tree_query", "overflow_query"],
   },
   {
     id: "memory-management",