Moves the event timeline to the personal dashboard from the header when
the `frontendHeaderRedesign` flag is active.
When the flag is active, it also:
- hides the event timeline and corresponding button in the header
- renders the environment selector next to the time selector instead of
at the other end of the header

---------
Co-authored-by: Nuno Góis <github@nunogois.com>
Follow-up to: https://github.com/Unleash/unleash/pull/8642
Introduces a reusable `Highlight` component that leverages the Context
API pattern, enabling highlight effects to be triggered from anywhere in
the application.
This update refactors the existing highlight effect in the event
timeline to use the new Highlight component and extends the
functionality to include the Unleash AI experiment, triggered by its
entry in the "New in Unleash" section.
https://linear.app/unleash/issue/2-2729/add-event-timeline-to-new-in-unleash
Adds the new event timeline to the "New in Unleash" section.
Unlike Signals & Actions, the Event timeline doesn’t have a dedicated
page to link to, as it's a global component within the layout. To
address this, we extend the "check it out" action in the New in Unleash
component by supporting a callback instead of a link. When the user
clicks "check it out" for this new item, the page smoothly scrolls to
the top, ~~the timeline opens (if it's not already)~~, and a temporary
highlight effect is triggered on the timeline header button.
Also includes some scouting / slight UX adjustments.
https://github.com/user-attachments/assets/fe49f21b-5986-46b2-8fc6-acb4daef9d08
https://linear.app/unleash/issue/2-2703/align-with-ux
Timeline UI/UX improvements after sync with UX, including:
- Added some spacing between each event in the grouping tooltip
- Aligned the x events occurred header with filter dropdown
- Improved the strategy icon somewhat so it doesn't look as off center
- New timeline icon
- Improve icon position relative to timestamp on each event in the
grouping tooltip
- Changed text color in dropdowns to a lighter gray
- Removed bold formatting in tooltip
- Adjusted paddings and margins
- Added close button
- Added shadow
- Added left border
There are a few details missing, which will be tackled in separate PRs.

---------
Co-authored-by: Nuno Góis <github@nunogois.com>
https://linear.app/unleash/issue/2-2662/make-the-event-timeline-available-globally-through-a-new-header-buttonhttps://github.com/user-attachments/assets/bde38ee8-cdd8-409d-a95e-0c06189e3d9b
(In the video, you’ll notice a slight delay before new events show up.
This happens because the timeline automatically refreshes every 10
seconds)
Removes the event timeline from the event log and integrates it into a
new header option.
I chose a middle-ground approach between options 1 and 2 from our Figma
sketches. This solution provides the best of both worlds IMO: the
timeline stands out as a global component, distinct from the current
page context, while sliding in rather than overlapping the content. This
way, users can view the timeline alongside the page content.
## About the changes
Instead of this:
```ts
const { uiConfig } = useUiConfig();
const myFlag = Boolean(uiConfig?.flags?.myFlag)
```
we can have this:
```ts
const myFlag = useUiFlag("myFlag")
```
With the same type safety, less verbose and more purposeful code.
### Important files
- `frontend/src/hooks/useUiFlag.ts`
## Discussion points
Can we in the future share flags between frontend and backend? Right now
adding a new flag has to be done in 4 different places (backend flag
keys list, backend flags defaults config, backend experimental server
options, frontend type).
Most ergonomic option is to pull config directly from Unleash.
Issue, based on previous user feedback:
https://github.com/Unleash/unleash/issues/4565
Internal feature request document:
[docs.google.com/document/d/1Sx0q...](https://docs.google.com/document/d/1Sx0qKZXUVUCjuY5F4MOh1ieOM1A2_jE58zEA7jaM_1g/edit?usp=sharing)