docs(skills): add ui-feature-testing skill for VS Code E2E verification

See merge request !3264

Merged-by: Olena Horal-Koretska <ohoralkoretska@gitlab.com>
Approved-by: Juhee Lee <julee@gitlab.com>
Approved-by: Tomas Vik <tvik@gitlab.com>
Approved-by: Tristan Read <tread@gitlab.com>
Reviewed-by: GitLab Duo <gitlab-duo@gitlab.com>
Co-authored-by: Tomas Vik <tvik@gitlab.com>

docs: update frontmatter metadata to reflect new stage and group values

See merge request !3272

Merged-by: Juhee Lee <julee@gitlab.com>
Approved-by: Juhee Lee <julee@gitlab.com>
Co-authored-by: Uma Chandran <uchandran@gitlab.com>

feat: bundle OAuth client ID for jihulab.com authentication

Closes #2292

See merge request !3215

Merged-by: Olena Horal-Koretska <ohoralkoretska@gitlab.com>
Approved-by: Olena Horal-Koretska <ohoralkoretska@gitlab.com>
Approved-by: James Casey <jcasey@gitlab.com>
Reviewed-by: James Casey <jcasey@gitlab.com>
Co-authored-by: zhaopeng <pengzhao@gitlab.cn>

# **pre-release**  [6.85.0](v6.84.5...v6.85.0) (2026-07-07)
### ✨ Features

* bundle OAuth client ID for jihulab.com authentication ([80f39155](80f39155)) by zhaopeng

### 📝 Documentation

* **skills:** add ui-feature-testing skill for VS Code E2E verification ([cf810b82](cf810b82)) by Olena Horal-Koretska
* update frontmatter metadata to reflect new stage and group values ([57f553e1](57f553e1)) by Uma Chandran