Verify that the ROS plugin displays clear, actionable error messages when hybrid cloud service account credentials are invalid.

Related issue: FLPATH-2746

Test Steps:
1. Deploy RHDH with ROS plugin (version 1.2.1+)
2. Configure ROS with invalid/non-existent hybrid cloud service account credentials
3. Browse to the optimization plugin section in RHDH
4. Observe the error messages in UI and backstage logs

Expected Results:

• UI displays clear error indicating hybrid cloud API authentication failure
• Backstage logs specifically state the problem is with hybrid cloud console API authentication
• Error messages do not mislead users to troubleshoot Backstage auth instead of hybrid cloud SA