- Introduced `Source` field to usage-related structs for better origin tracking.
- Updated `newUsageReporter` to resolve and populate the `Source` attribute.
- Implemented `resolveUsageSource` to determine source from auth metadata or API key.
- Switched to a slice-based queue with mutex and condition variable for better control over queuing and dispatching.
- Removed fixed buffer size to handle dynamic queuing.
- Enhanced shutdown logic to safely close the queue and wake up waiting goroutines.
- Added `LoggerPlugin` to log usage metrics for observability.
- Introduced a new `Manager` to handle usage record queuing and plugin registration.
- Integrated new usage reporter and detailed metrics parsing into executors, covering providers like OpenAI, Codex, Claude, and Gemini.
- Improved token usage breakdown across streaming and non-streaming responses.
