docs: 添加 ToolSearch 设计指南 + 禁用 turn-zero 工具推荐弹窗

- 新增 docs/design/tool-search-design-guide.md，涵盖架构、搜索算法、执行管道、演进历史
- 禁用 getTurnZeroSearchExtraToolsPrefetch，消除用户输入时的频繁弹窗
- inter-turn 发现机制保持不变

Co-Authored-By: glm-5-turbo <zai-org@claude-code-best.win>

src/commands/commit-push-pr.ts

@@ -18,7 +18,7 @@ const ALLOWED_TOOLS = [
   'Bash(gh pr edit:*)',
   'Bash(gh pr view:*)',
   'Bash(gh pr merge:*)',
-  'ToolSearch',
+  'SearchExtraTools',
   'mcp__slack__send_message',
   'mcp__claude_ai_Slack__slack_send_message',
 ]
@@ -45,7 +45,7 @@ function getPromptContent(
 <!-- CHANGELOG:END -->`
   let slackStep = `
 
-5. After creating/updating the PR, check if the user's CLAUDE.md mentions posting to Slack channels. If it does, use ToolSearch to search for "slack send message" tools. If ToolSearch finds a Slack tool, ask the user if they'd like you to post the PR URL to the relevant Slack channel. Only post if the user confirms. If ToolSearch returns no results or errors, skip this step silently—do not mention the failure, do not attempt workarounds, and do not try alternative approaches.`
+5. After creating/updating the PR, check if the user's CLAUDE.md mentions posting to Slack channels. If it does, use SearchExtraTools to search for "slack send message" tools. If SearchExtraTools finds a Slack tool, ask the user if they'd like you to post the PR URL to the relevant Slack channel. Only post if the user confirms. If SearchExtraTools returns no results or errors, skip this step silently—do not mention the failure, do not attempt workarounds, and do not try alternative approaches.`
   if (process.env.USER_TYPE === 'ant' && isUndercover()) {
     prefix = getUndercoverInstructions() + '\n'
     reviewerArg = ''