fix: 合并后清理重复测试与修复 CEO/财务兜底脚本注入 bug

- apply-ceo-finance-fallback.js: execute() 原先在传入 mock pool 时仍强制要求
  DATABASE_URL 环境变量,导致单测无法注入 mock pool 验证事务逻辑。改为仅在
  未传入 pool 时才检查 DATABASE_URL。
- portal.test.js: 删除本次合并前遗留的重复用例(期望旧的
  portal.feature_disabled reasonCode),候选分支自带的等价用例更完整
  (校验 reasonCode 以及全部零写入断言)。
- todos.test.js: 删除本次合并前遗留的文件,候选分支的
  todos.errors.test.js 覆盖等价且更完整。

server/tests/unit/routes/portal.test.js

@@ -573,26 +573,4 @@ describe("portal routes", () => {
     await app.close();
   });
 
-  it("returns a precise reasonCode and skips business queries when portal home is disabled", async () => {
-    featureFlagState.portalHome = false;
-    const { app, prisma } = await buildApp({});
-
-    const response = await app.inject({
-      method: "GET",
-      url: "/api/portal/home",
-      headers: { authorization: "Bearer test" },
-    });
-
-    expect(response.statusCode).toBe(409);
-    expect(response.json()).toMatchObject({
-      error: {
-        code: "VALID_001",
-        details: { featureFlag: "portal_home_v1_disabled", reason: "env_hard_off", reasonCode: "portal.feature_disabled" },
-      },
-    });
-    expect(prisma.reimbursementForm.count).not.toHaveBeenCalled();
-    expect(prisma.workflowTask.count).not.toHaveBeenCalled();
-
-    await app.close();
-  });
 });