## Problem
We now export components under a subpath in ui-patterns to avoid barrel
files as they slow down every tools (from IDE to linters, etc.) and may
also affect bundles our users have to download.
## Solution
- Remove the UI patterns index file
- Fix invalid impors
## Problem
We have many unused files, left overs from features refactoring
## Solution
- Remove unused files
- Move some files closer to their usage
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Refactor**
* Removed multiple legacy Studio UI components and placeholders to
streamline the interface (including onboarding panels, navigation
elements, docs layout helpers, and various UI building blocks).
* **UI Updates**
* Updated the layout’s API keys section to use the Project-specific
presentation.
* **Maintenance**
* Adjusted internal sourcing for documentation tab menu logic without
changing visible behavior.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Gildas Garcia