Sychronize users between people depot and kb

### Blockers/Dependencies
None

### Overview
REPLACE THIS TEXT -Text here that clearly states the purpose of this issue in 2 sentences or less.

### Action Items
- [ ] User synch
- [ ] If PEOPLE_DEPOT_URL is defined in kb when user logs in, confirm PEOPLE_DEPOT URL works. If it doesn't work, error message and prevent creation of user.
- [ ] Prevent creation of user in KB ifcannot create in PD
- [ ] Manual tests
- [ ] Sign up for account in kb.
- From sqlite browser
- verify account is created in PD
- verify account is created in BD
- Compare user account in PD and KB
- compare to Cognito
- Log in to kb using new account - verify message no authorization
- Log in to pd using new account- verify message no authorization
- Test API call from kb to pd
- Verify call people depot URL indicates authenticated but not authorized
- Set is_staff to true in PD
- Verify call people depot urlworks
- Document manual tests
- [ ] Sign up for account in pd.
- From sqlite browser
- verify account is created in PD
- sign in to using KB cognito account
- verify account is created in KB
- Compare user account in PD and KB
- compare to Cognito
- Log in to kb using new account - verify message no authorization
- Log in to pd using new account- verify message no authorization
- Test API call from kb to pd
- Verify call people depot URL indicates authenticated but not authorized
- Set is_staff to true in PD
- Verify call people depot urlworks
- Document manual tests
- [ ] Implement and test updating user in kb, see gets changed in pd
- [ ] Decide on strategy on
- what to do if pd is down and new account is created - how to eventually resynch

REPLACE THIS TEXT -If the issue has already been researched, and the course of action is clear, this will describe the steps. However, if the steps can be divided into tasks for more than one person, we recommend dividing it up into separate issues, or assigning it as a pair programming task.

### How to Manually Verify
REPLACE THIS TEXT - Describe how to manually verify either through UI or executing the code and inspecting.

### Automated Tests
Any automated tests?

### Resources/Instructions
REPLACE THIS TEXT -If there is a website which has documentation that helps with this issue provide the link(s) here.

首先追踪注册和登录路径以及 PEOPLE_DEPOT_URL 集成；issue 中未指定源文件或自动化测试。将列出的 KB、People Depot 和 Cognito 手动检查作为验证计划，包括不可用服务的处理和用户更新。完成意味着同步行为和重新同步策略已达成一致、实现、测试并记录在文档中。

由索引模型根据 Issue 内容生成。