[Linked Account] fix bad request after link

[KayMKM]

Purpose

What is the context of this pull request? Why is it being done?
fix: #3444

Changes

Are there any changes that need to be called out as significant or particularly difficult to grasp? (Include illustrative screenshots for context if applicable.)

1. add user id in activity to get auth link.
2. remove logic of generate new user id in home controller to avoid user id be changed after refresh the page.

Tests

Is this covered by existing tests or new ones? If no, why not?

Feature Plan

Are there any remaining steps or dependencies before this issue can be fully resolved? If so, describe and link to any relevant pull requests or issues.

Checklist

General

• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the appropriate tests
• I have updated related documentation