Add UI test for AuthPolicy form view

[emmaaroche]

Details

AuthPolicy form has: policy name, target gateway, authentication rules, authorization rules, response configuration. Most complex form with multiple expandable sections.

Checklist

• Policy name required field validation
• Target gateway selector validation
• Authentication rules section
• Authorization rules section
• Response configuration section
• Expandable sections toggle correctly
• Form/YAML toggle preserves data
• Form submission creates resource
• Edit mode loads existing resource