fix(ci): resolve mock.module() cross-file leakage in test suite

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/features/background-agent/session-status-classifier.test.ts

@@ -1,11 +1,13 @@
 import { describe, test, expect, mock, afterAll } from "bun:test"
-import { isActiveSessionStatus, isTerminalSessionStatus } from "./session-status-classifier"
 
 const mockLog = mock()
 mock.module("../../shared", () => ({ log: mockLog }))
 
 afterAll(() => { mock.restore() })
 
+const { isActiveSessionStatus, isTerminalSessionStatus } = await import("./session-status-classifier")
+mock.restore()
+
 describe("isActiveSessionStatus", () => {
   describe("#given a known active session status", () => {
     test('#when type is "busy" #then returns true', () => {