Manually initiate Google OAuth authentication flow.
NOTE: This tool should typically NOT be called directly. The authentication system
automatically handles credential checks and prompts for authentication when needed.
Only use this tool if:
1. You need to re-authenticate with different credentials
2. You want to proactively authenticate before using other tools
3. The automatic authentication flow failed and you need to retry
In most cases, simply try calling the Google Workspace tool you need - it will
automatically handle authentication if required.
