- Introduced `SystemInstruction` field in `PrepareRequest` and `GenerateContentRequest` for better message parsing.
- Updated `SendMessage` and `SendMessageStream` to handle system instructions in client API calls.
- Enhanced error handling and manual flushing logic in response flows.
- Added new internal API endpoints `/v1internal:generateContent` and `/v1internal:streamGenerateContent`.
- Improved proxy handling and transport logic in HTTP client initialization.
- Consolidated `TokenStorage` struct into `internal/auth/models.go` for better organization.
- Updated `Client` to use `TokenStorage` for managing email and project ID.
- Simplified `SetupUser` method to ensure proper token and project assignment.
- Refactored API handlers to leverage new `GetEmail` and `GetProjectID` methods in `Client`.
- Cleanup: Removed unused structures and redundant code from `client.go` and `auth.go`.
- Adjusted CLI flow in `login.go` and `run.go` for streamlined user onboarding.