feat: 实现 Tool Search 基础设施层（CORE_TOOLS 白名单 + TF-IDF 索引 + ExecuteTool + 搜索增强）

- 新增 CORE_TOOLS 白名单常量（31 个核心工具），重构 isDeferredTool 为白名单制判定
- 新建 TF-IDF 工具索引模块（toolIndex.ts），复用 localSearch.ts 算法函数
- 新建 ExecuteTool 跨 API provider 统一工具执行入口
- 增强 ToolSearchTool：TF-IDF 搜索路径、discover: 模式、并行搜索合并、文本模式回退
- 新增 27 个单元测试，precheck 零错误通过（4108 tests pass）

Co-Authored-By: glm-5.1[1m] <zai-org@claude-code-best.win>

src/constants/tools.ts

@@ -22,8 +22,14 @@ import { TASK_CREATE_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/Tas
 import { TASK_GET_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/TaskGetTool/constants.js'
 import { TASK_LIST_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/TaskListTool/constants.js'
 import { TASK_UPDATE_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/TaskUpdateTool/constants.js'
-import { TOOL_SEARCH_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/ToolSearchTool/prompt.js'
+import { TOOL_SEARCH_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/ToolSearchTool/constants.js'
 import { SYNTHETIC_OUTPUT_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/SyntheticOutputTool/SyntheticOutputTool.js'
+import { SLEEP_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/SleepTool/prompt.js'
+import { LSP_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/LSPTool/prompt.js'
+import { VERIFY_PLAN_EXECUTION_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/VerifyPlanExecutionTool/constants.js'
+import { TEAM_CREATE_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/TeamCreateTool/constants.js'
+import { TEAM_DELETE_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/TeamDeleteTool/constants.js'
+import { EXECUTE_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/ExecuteTool/constants.js'
 import { ENTER_WORKTREE_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/EnterWorktreeTool/constants.js'
 import { EXIT_WORKTREE_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/ExitWorktreeTool/constants.js'
 import { WORKFLOW_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/WorkflowTool/constants.js'
@@ -110,3 +116,52 @@ export const COORDINATOR_MODE_ALLOWED_TOOLS = new Set([
   SEND_MESSAGE_TOOL_NAME,
   SYNTHETIC_OUTPUT_TOOL_NAME,
 ])
+
+/**
+ * Core tools that are always loaded with full schema at initialization.
+ * These tools are never deferred — they appear in the initial prompt.
+ * All other tools (non-core built-in + all MCP tools) are deferred
+ * and must be discovered via ToolSearchTool / ExecuteTool.
+ */
+export const CORE_TOOLS = new Set([
+  // File operations
+  ...SHELL_TOOL_NAMES, // 'Bash', 'Shell'
+  FILE_READ_TOOL_NAME, // 'Read'
+  FILE_EDIT_TOOL_NAME, // 'Edit'
+  FILE_WRITE_TOOL_NAME, // 'Write'
+  GLOB_TOOL_NAME, // 'Glob'
+  GREP_TOOL_NAME, // 'Grep'
+  NOTEBOOK_EDIT_TOOL_NAME, // 'NotebookEdit'
+  // Agent & interaction
+  AGENT_TOOL_NAME, // 'Agent'
+  ASK_USER_QUESTION_TOOL_NAME, // 'AskUserQuestion'
+  SEND_MESSAGE_TOOL_NAME, // 'SendMessage'
+  // Team (swarm)
+  TEAM_CREATE_TOOL_NAME, // 'TeamCreate'
+  TEAM_DELETE_TOOL_NAME, // 'TeamDelete'
+  // Task management
+  TASK_OUTPUT_TOOL_NAME, // 'TaskOutput'
+  TASK_STOP_TOOL_NAME, // 'TaskStop'
+  TASK_CREATE_TOOL_NAME, // 'TaskCreate'
+  TASK_GET_TOOL_NAME, // 'TaskGet'
+  TASK_LIST_TOOL_NAME, // 'TaskList'
+  TASK_UPDATE_TOOL_NAME, // 'TaskUpdate'
+  TODO_WRITE_TOOL_NAME, // 'TodoWrite'
+  // Planning
+  ENTER_PLAN_MODE_TOOL_NAME, // 'EnterPlanMode'
+  EXIT_PLAN_MODE_V2_TOOL_NAME, // 'ExitPlanMode'
+  VERIFY_PLAN_EXECUTION_TOOL_NAME, // 'VerifyPlanExecution'
+  // Web
+  WEB_FETCH_TOOL_NAME, // 'WebFetch'
+  WEB_SEARCH_TOOL_NAME, // 'WebSearch'
+  // Code intelligence
+  LSP_TOOL_NAME, // 'LSP'
+  // Skills
+  SKILL_TOOL_NAME, // 'Skill'
+  // Scheduling & monitoring
+  SLEEP_TOOL_NAME, // 'Sleep'
+  // Tool discovery (always loaded)
+  TOOL_SEARCH_TOOL_NAME, // 'ToolSearch'
+  EXECUTE_TOOL_NAME, // 'ExecuteTool'
+  SYNTHETIC_OUTPUT_TOOL_NAME, // 'SyntheticOutput'
+]) as ReadonlySet<string>