fix(tests): stabilize toast manager and continuation tests

src/features/task-toast-manager/manager.test.ts

@@ -1,17 +1,20 @@
-import { describe, test, expect, beforeEach, mock } from "bun:test"
-import { TaskToastManager } from "./manager"
+declare const require: (name: string) => any
+const { describe, test, expect, beforeEach, afterEach, mock } = require("bun:test")
 import type { ConcurrencyManager } from "../background-agent/concurrency"
 
+type TaskToastManagerClass = typeof import("./manager").TaskToastManager
+
 describe("TaskToastManager", () => {
+  let TaskToastManager: TaskToastManagerClass
   let mockClient: {
     tui: {
       showToast: ReturnType<typeof mock>
     }
   }
-  let toastManager: TaskToastManager
+  let toastManager: InstanceType<TaskToastManagerClass>
   let mockConcurrencyManager: ConcurrencyManager
 
-  beforeEach(() => {
+  beforeEach(async () => {
     mockClient = {
       tui: {
         showToast: mock(() => Promise.resolve()),
@@ -20,10 +23,18 @@ describe("TaskToastManager", () => {
     mockConcurrencyManager = {
       getConcurrencyLimit: mock(() => 5),
     } as unknown as ConcurrencyManager
+
+    const mod = await import("./manager")
+    TaskToastManager = mod.TaskToastManager
+
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     toastManager = new TaskToastManager(mockClient as any, mockConcurrencyManager)
   })
 
+  afterEach(() => {
+    mock.restore()
+  })
+
   describe("skills in toast message", () => {
     test("should display skills when provided", () => {
       // given - a task with skills

src/features/task-toast-manager/manager.ts

@@ -217,3 +217,7 @@ export function initTaskToastManager(
   instance = new TaskToastManager(client, concurrencyManager)
   return instance
 }
+
+export function _resetTaskToastManagerForTesting(): void {
+  instance = null
+}