Change key validation endpoint from portal to API across all clients:
- C: Update PORTAL_BASE to API_BASE in validate_api_key()
- Python (sync/async): Change PORTAL_BASE to API_BASE
- Perl: Change $PORTAL_BASE to $API_BASE
- Rust (sync/async): Change hardcoded URL to api.unsandbox.com
All other languages (Go, Java, Kotlin, C#, Ruby, PHP, JavaScript) already
use their makeRequest() function with API_BASE, so no changes needed.
The key subcommand already exists and continues to work with the new endpoint.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>