Frontend: Update the catalog icon in the pipeline editor

Insight

It could be easily missed to identify the Browse CI/CD Catalog button in the pipeline editor.

Supporting evidence

• Dovetail insight (internal)

Action

Replace the external link icon with the catalog icon and rename the button without using the verb.

Resources

• 🕊 Dovetail project
• 🔍 Research issue
• 👣 See other recommendation issues

Tasks

• Assign this issue to the appropriate Product Manager, Product Designer, or UX Researcher.
• Add the appropriate Group (such as ~"group::source code") label to the issue. This helps identify and track actionable insights at the group level.
• Link this issue back to the original research issue in the GitLab UX Research project and the Dovetail project.
• Adjust confidentiality of this issue if applicable