Enable user model selection for cloud-connected self-managed
What does this MR do and why?
Enable user model selection for cloud-connected self-managed
Changes:
- Updated
DuoAgentPlatformModelMetadataServiceto support user model selection for cloud-connected instances - Added parallel instance-level methods that mirror namespace-level logic to avoid breaking existing .com functionality
- Added comprehensive test coverage for pinned and unpinned model scenarios with user selection enabled/disabled
Related to #577247