Action focused merge request homepage
## Proposal
The current issue proposes ways to clarify who has responsibility for a merge request, whether it's a reviewer who has been requested to review, an author who needs to respond to a finished review, or a reviewer who has been re-requested to review.
### Problem
Users are having trouble identifying which MRs require their immediate attention, whether it's responding to feedback as an author or reviewing pending MRs as a reviewer. The problem originates from the current interface and the lack of a notification system, making it hard to tell which MRs need action and which don't.
As a result, people can't effectively maintain a smooth collaboration within the development workflow. To fix this, a category system is needed that highlights MRs based on what action is needed, making it easier for authors and reviewers to prioritize their tasks and streamline the development workflow.
As stated [here with the previous efforts for "Attention requests"](https://gitlab.com/groups/gitlab-org/-/epics/5331#vision "Merge requests that require my attention"), GitLab should make it easy to distinguish between MRs that require your attention and MRs that don't.
* As an author (Assignee/Author): Which MRs have reviewers responded to that I need to address their feedback on?
* As a reviewer (Reviewer): Which MRs need my review or approval?
## Outcomes
- Minimize the time it takes to recognize that a code review has been requested
- Minimize the likelihood that your code review requests are incorrectly categorized or ordered.
- Minimize the likelihood of selecting a low-priority code review request to address when there are more important reviews
## Lists
- `Returned to you` - Reviewers left feedback, or requested changes from you, on these merge requests.
- `Reviews requested` - These merge requests need a review from you.
- `Assigned to you` - You're assigned to these merge requests, but they don't have reviewers yet.
- `Waiting for others` - Your assigned merge requests that are waiting for approvals, and reviews you have requested changes for.
- `Approved by you` - You've reviewed and approved these merge requests.
- `Approved by others` - Includes all merge requests you are assigned to and a reviewer has approved.
- `Merged recently` - These merge requests merged after %{date: 14 days ago}. You were an assignee or a reviewer.
## Decision log
- `2024-11-14`: Team discusses ([recorded meeting](https://www.youtube.com/watch?v=5vNt6Eh7Z5s)) moving away from the naming of "Needs attention" and "Following" and designs will be explored in https://gitlab.com/gitlab-org/gitlab/-/issues/504685+
- `2024-09-26`: Designs to introduce tabs "Needs attention" and "Following" as a solution to only show those that add to the count https://gitlab.com/gitlab-org/gitlab/-/issues/493981.
- `2024-08-14`: Pilot internal testing. Ended 2024-10-10.
- Survey pre/post testing https://gitlab.com/gitlab-org/ux-research/-/issues/3214+.
- `2024-07-01`: Recommendation a plan for moving on development for internal testing ([video](https://youtu.be/4IvtYlvq4yI)) https://gitlab.com/gitlab-org/ux-research/-/issues/2986#note_1976086363
- `2024-06-18`: An internal test with GitLab engineers has been completed ([UserTesting](https://app.usertesting.com/workspaces/509645#!/study/5174376/sessions), [Dovetail](https://gitlab.dovetail.com/projects/5e7tcZtpNr66Hvw5EwGWqj/v/1qtOJlCXXDopFKMTFPZDrI)).
- `2024-06-06`: Concept of a singular list to combine assigned and reviews https://gitlab.com/gitlab-org/gitlab/-/issues/430735#note_1938131828
- [Challenge highlighted](https://gitlab.com/gitlab-org/gitlab/-/issues/430735#note_1997149080) with a search on top of a singluar MR list.
- "_...a single overview page without any clear indication of what's going on is a pretty massive regression_" ([comment](https://gitlab.com/gitlab-org/gitlab/-/issues/430735#note_1939576490))
- `2024-04-04`: Research insights on labelling of the type of merge request state/attention ([comment](https://gitlab.com/gitlab-org/gitlab/-/issues/430735#note_1845544781) - https://gitlab.com/gitlab-org/ux-research/-/issues/2964).
- `2023-11-23`: Original design with 4 boxes "My merge requests: Needs my attention", "My merge requests: Waiting on reviews", "My code reviews: Needs my review", "My code reviews: Reviews I have submitted".
## Latest design
2024-09-26 Introduced "Needs attention" and "Following https://gitlab.com/gitlab-org/gitlab/-/issues/493981#note_2129463103
| Needs attention | Following | Search |
| ------ | ------ | ------ |
|  |  |  |
<details><summary>2024-07-01 Design</summary>

</details>
epic