fix: 清理 useReplBridge pendingPermissionHandlers，修复 RC 权限条目保留内存泄漏

pendingPermissionHandlers Map 原定义在 async IIFE 内部，组件卸载时
cleanup 函数无法访问。修复方案：
- 将 Map 提升至 useEffect 顶层作用域
- cleanup 时显式调用 pendingPermissionHandlers.clear() 释放闭包引用
- 添加 8 个测试覆盖 handler 注册/取消/响应/cleanup 模式

同时确认 #4 空闲渲染循环已完整实现（所有 10 个 useAnimationFrame
调用者均正确传递 null 暂停时钟）。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/hooks/__tests__/replBridgePermissionHandlers.test.ts

@@ -0,0 +1,114 @@
+import { describe, expect, test } from 'bun:test'
+
+/**
+ * Tests for the pendingPermissionHandlers cleanup pattern used in
+ * useReplBridge.tsx. The handlers Map tracks in-flight permission
+ * requests; the cleanup function must clear it on unmount to release
+ * closures that capture React state.
+ *
+ * The actual hook is deeply integrated with React/bridge lifecycle,
+ * so these tests validate the Map management pattern in isolation.
+ */
+
+type PermissionHandler = (response: { approved: boolean }) => void
+
+function createPermissionHandlersMap() {
+  const handlers = new Map<string, PermissionHandler>()
+
+  return {
+    handlers,
+    onResponse(requestId: string, handler: PermissionHandler): () => void {
+      handlers.set(requestId, handler)
+      return () => {
+        handlers.delete(requestId)
+      }
+    },
+    handleResponse(requestId: string, response: { approved: boolean }): boolean {
+      const handler = handlers.get(requestId)
+      if (!handler) return false
+      handlers.delete(requestId)
+      handler(response)
+      return true
+    },
+    cleanup(): void {
+      handlers.clear()
+    },
+    size(): number {
+      return handlers.size
+    },
+  }
+}
+
+describe('pendingPermissionHandlers cleanup pattern', () => {
+  test('onResponse registers a handler', () => {
+    const map = createPermissionHandlersMap()
+    map.onResponse('req-1', () => {})
+    expect(map.size()).toBe(1)
+  })
+
+  test('onResponse returns a cancel function', () => {
+    const map = createPermissionHandlersMap()
+    const cancel = map.onResponse('req-1', () => {})
+    expect(map.size()).toBe(1)
+    cancel()
+    expect(map.size()).toBe(0)
+  })
+
+  test('handleResponse dispatches to handler and removes it', () => {
+    const map = createPermissionHandlersMap()
+    let received: { approved: boolean } | null = null
+    map.onResponse('req-1', (resp) => { received = resp })
+    const dispatched = map.handleResponse('req-1', { approved: true })
+    expect(dispatched).toBe(true)
+    expect(received).toEqual({ approved: true })
+    expect(map.size()).toBe(0)
+  })
+
+  test('handleResponse returns false for unknown requestId', () => {
+    const map = createPermissionHandlersMap()
+    const dispatched = map.handleResponse('unknown', { approved: true })
+    expect(dispatched).toBe(false)
+  })
+
+  test('cleanup clears all registered handlers', () => {
+    const map = createPermissionHandlersMap()
+    map.onResponse('req-1', () => {})
+    map.onResponse('req-2', () => {})
+    map.onResponse('req-3', () => {})
+    expect(map.size()).toBe(3)
+
+    map.cleanup()
+
+    expect(map.size()).toBe(0)
+  })
+
+  test('handlers are not dispatched after cleanup', () => {
+    const map = createPermissionHandlersMap()
+    let called = false
+    map.onResponse('req-1', () => { called = true })
+
+    map.cleanup()
+
+    // Late-arriving response after cleanup should not find a handler
+    const dispatched = map.handleResponse('req-1', { approved: true })
+    expect(dispatched).toBe(false)
+    expect(called).toBe(false)
+  })
+
+  test('cancel function is a no-op after cleanup', () => {
+    const map = createPermissionHandlersMap()
+    const cancel = map.onResponse('req-1', () => {})
+    map.cleanup()
+    // Should not throw
+    expect(() => cancel()).not.toThrow()
+  })
+
+  test('cleanup can be called multiple times safely', () => {
+    const map = createPermissionHandlersMap()
+    map.onResponse('req-1', () => {})
+    map.cleanup()
+    map.cleanup()
+    map.cleanup()
+    expect(map.size()).toBe(0)
+  })
+})