- Update Go version to 1.26.10 across modules.
- Update indirect and direct dependencies including go-git, golang.org/x packages, and plugin go.mod files.
- Introduced `FrontendAuthProviderExclusive` capability to restrict authentication to a single selected provider.
- Added `SetExclusiveProvider` and `ClearExclusiveProvider` methods for managing exclusive providers in the access registry.
- Updated `pluginhost` to prioritize and enforce exclusive providers based on plugin priority and ID.
- Enhanced RPC capabilities schema to include `FrontendAuthProviderExclusive` field.
- Added example plugin and tests for exclusive frontend auth behavior.