<!-- CURSOR_SUMMARY -->
> [!NOTE]
> Ensures GitHub disconnect fully removes credentials and verifies via
targeted e2e coverage.
> 
> - Clear both `githubAccessToken` and `githubUser` in
`GitHubIntegration` when disconnecting
> - New Playwright test `github clear integration settings` verifies the
disconnect button disappears and snapshots only the settings delta
> - Test helpers: add `captureSettings()` and `snapshotSettingsDelta()`
to diff `user-settings.json` for concise snapshots
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
0c47bee06d145737e10c58c8133da35c0c9553bb. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

<!-- This is an auto-generated description by cubic. -->
---
## Summary by cubic
Disconnecting from GitHub now clears both the access token and user info
to prevent stale credentials. Added an e2e test to verify the settings
file is cleaned and the UI updates correctly.

- **Bug Fixes**
  - Clear githubUser alongside githubAccessToken on disconnect.
- Added Playwright e2e to ensure both fields are removed and the
disconnect button disappears.

<sup>Written for commit 0c47bee06d145737e10c58c8133da35c0c9553bb.
Summary will update on new commits.</sup>

<!-- End of auto-generated description by cubic. -->

---------
Co-authored-by: William Chen <will@mac.lan>