Agents - update icon for custom group section - #331775

PR classified as team-member.

✅ Head commit f9a2a29 is signed by lszomoru with trusted key 9DC97B63EF3D785A1C683E6C93C4A84272843F4E — approval requirement reduced from 2 to 1.

✅ Collaborator approvals: 1/1 (benibenj).

✅ No newly added runnable binary files.

✅ No protected engineering system files changed.