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/components/ToolSearchHint.tsx

@@ -0,0 +1,53 @@
+import * as React from 'react';
+import { Box, Text } from '@anthropic/ink';
+import { Select } from './CustomSelect/select.js';
+import { PermissionDialog } from './permissions/PermissionDialog.js';
+
+type ToolSearchHintItem = {
+  name: string;
+  description: string;
+  score: number;
+};
+
+type Props = {
+  tools: ToolSearchHintItem[];
+  onSelect: (toolName: string) => void;
+  onDismiss: () => void;
+};
+
+const AUTO_DISMISS_MS = 30_000;
+
+export function ToolSearchHint({ tools, onSelect, onDismiss }: Props): React.ReactNode {
+  const onSelectRef = React.useRef(onSelect);
+  const onDismissRef = React.useRef(onDismiss);
+  onSelectRef.current = onSelect;
+  onDismissRef.current = onDismiss;
+
+  React.useEffect(() => {
+    const timeoutId = setTimeout(ref => ref.current(), AUTO_DISMISS_MS, onDismissRef);
+    return () => clearTimeout(timeoutId);
+  }, []);
+
+  const options = tools.map(t => ({
+    label: `${t.name} — ${t.description.slice(0, 60)} (score: ${t.score.toFixed(2)})`,
+    value: t.name,
+  }));
+
+  options.push({ label: 'Dismiss', value: '__dismiss__' });
+
+  return (
+    <PermissionDialog title="Tool Recommendation">
+      <Select
+        options={options}
+        onChange={value => {
+          if (value === '__dismiss__') {
+            onDismissRef.current();
+          } else {
+            onDismissRef.current();
+            onSelectRef.current(value);
+          }
+        }}
+      />
+    </PermissionDialog>
+  );
+}

src/components/__tests__/ToolSearchHint.test.ts

@@ -0,0 +1,80 @@
+import { describe, test, expect, beforeEach } from 'bun:test'
+import { mock } from 'bun:test'
+import { logMock } from '../../../tests/mocks/log'
+import { debugMock } from '../../../tests/mocks/debug'
+
+mock.module('src/utils/log.ts', logMock)
+mock.module('src/utils/debug.ts', debugMock)
+mock.module('src/services/analytics/growthbook.js', () => ({
+  getFeatureValue_CACHED_MAY_BE_STALE: () => false,
+  checkStatsigFeatureGate_CACHED_MAY_BE_STALE: () => false,
+  getFeatureValue_DEPRECATED: async () => undefined,
+  getFeatureValue_CACHED_WITH_REFRESH: async () => undefined,
+  hasGrowthBookEnvOverride: () => false,
+  getAllGrowthBookFeatures: () => ({}),
+  getGrowthBookConfigOverrides: () => ({}),
+  setGrowthBookConfigOverride: () => {},
+  clearGrowthBookConfigOverrides: () => {},
+  getApiBaseUrlHost: () => undefined,
+  onGrowthBookRefresh: () => {},
+  initializeGrowthBook: async () => {},
+  checkSecurityRestrictionGate: async () => false,
+  checkGate_CACHED_OR_BLOCKING: async () => false,
+  refreshGrowthBookAfterAuthChange: () => {},
+  resetGrowthBook: () => {},
+  refreshGrowthBookFeatures: async () => {},
+  setupPeriodicGrowthBookRefresh: () => {},
+  stopPeriodicGrowthBookRefresh: () => {},
+  getDynamicConfig_CACHED_MAY_BE_STALE: () => undefined,
+  getDynamicConfig_BLOCKS_ON_INIT: async () => undefined,
+}))
+
+const {
+  subscribeToToolSearchPrefetch,
+  getToolSearchPrefetchSnapshot,
+  clearToolSearchPrefetchResults,
+} = await import('src/services/toolSearch/prefetch.js')
+
+const { useToolSearchHint } = await import('src/hooks/useToolSearchHint.js')
+
+describe('useToolSearchHint', () => {
+  // We test the subscription/snapshot API directly since
+  // React hooks require a renderer.
+  test('returns empty tools when no prefetch result', () => {
+    clearToolSearchPrefetchResults()
+    const snapshot = getToolSearchPrefetchSnapshot()
+    expect(snapshot).toEqual([])
+  })
+
+  test('snapshot updates when listeners are notified', () => {
+    clearToolSearchPrefetchResults()
+
+    // Simulate what prefetch does: set results and notify
+    const mockSetResults = (results: unknown[]) => {
+      // We can't directly set latestPrefetchResult, but we can test
+      // the clear function and subscription mechanism
+      clearToolSearchPrefetchResults()
+    }
+
+    // Test subscription
+    let callCount = 0
+    const unsubscribe = subscribeToToolSearchPrefetch(() => {
+      callCount++
+    })
+    expect(callCount).toBe(0)
+
+    // Trigger a notification via clear
+    mockSetResults([])
+    expect(callCount).toBe(1)
+
+    // Unsubscribe and verify no more calls
+    unsubscribe()
+    clearToolSearchPrefetchResults()
+    expect(callCount).toBe(1)
+  })
+
+  test('clearToolSearchPrefetchResults resets snapshot', () => {
+    clearToolSearchPrefetchResults()
+    expect(getToolSearchPrefetchSnapshot()).toEqual([])
+  })
+})

src/components/messages/AttachmentMessage.tsx

@@ -138,7 +138,22 @@ export function AttachmentMessage({ attachment, addMargin, verbose, isTranscript
     }
   }
 
-  // eslint-disable-next-line @typescript-eslint/switch-exhaustiveness-check -- teammate_mailbox/skill_discovery handled before switch
+  // tool_discovery rendered here (not in the switch) so the 'tool_discovery'
+  // string literal stays inside a feature()-guarded block.
+  if (feature('EXPERIMENTAL_TOOL_SEARCH')) {
+    if (attachment.type === 'tool_discovery') {
+      if (attachment.tools.length === 0) return null;
+      const names = attachment.tools.map(t => t.name).join(', ');
+      return (
+        <Line>
+          <Text dimColor>Discovered tools: </Text>
+          <Text>{names}</Text>
+        </Line>
+      );
+    }
+  }
+
+  // eslint-disable-next-line @typescript-eslint/switch-exhaustiveness-check -- teammate_mailbox/skill_discovery/tool_discovery handled before switch
   switch (attachment.type) {
     case 'directory':
       return (
@@ -396,7 +411,12 @@ export function AttachmentMessage({ attachment, addMargin, verbose, isTranscript
       // skill_discovery and teammate_mailbox are handled BEFORE the switch in
       // runtime-gated blocks (feature() / isAgentSwarmsEnabled()) that TS can't
       // narrow through — excluded here via type union (compile-time only, no emit).
-      attachment.type satisfies NullRenderingAttachmentType | 'skill_discovery' | 'teammate_mailbox' | 'bagel_console';
+      attachment.type satisfies
+        | NullRenderingAttachmentType
+        | 'skill_discovery'
+        | 'tool_discovery'
+        | 'teammate_mailbox'
+        | 'bagel_console';
       return null;
   }
 }