- Implement extract_context to parse kubeconfig YAML and extract context name
- Implement extract_server_url to parse kubeconfig YAML and extract server URL
- Add empty content validation for kubeconfig
- Add YAML parsing error handling with actionable error messages
- Add delete_port_forward Rust command to remove port forwards from state
- Update tauriCommands.ts to use delete_port_forward command
- Register delete_port_forward in lib.rs invoke handler
