- 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.
- Implemented `RequestInterceptor`, `ResponseInterceptor`, and `StreamChunkInterceptor` capabilities.
- Added `sanitizePluginMetadata` to clean metadata for RPC compatibility.
- Enhanced interceptor chaining, error handling, and test coverage.
- Updated plugin configuration to register and dispatch interceptor methods.
- Removed `examples/plugin/main.go` and `internal/pluginhost/loader_plugin.go` after migrating to a more modular system.
- Introduced `streamBridge` in `internal/pluginhost/stream_bridge.go` for efficient stream handling and communication.
- Added examples of `thinking` plugins written in both Rust and Go under `examples/plugin/thinking`.
- Enhanced test coverage for plugin host system changes, including stream chunk translation and thinking logic.
- Improved API compatibility and ensured backward-compatible upgrades for plugin execution.
- Implemented command-line flag registration and execution for plugins with priority-based conflict resolution.
- Enabled plugin-owned command-line flag execution and persistence of plugin-auth data.
- Added new `Host` methods to support command-line capabilities, including flag normalization, validation, and execution state management.
- Introduced unit tests to ensure coverage for command-line plugin functionality, including auth data persistence.
- Updated configs to normalize plugins during initialization.
