Introduce `backtunnel-authorize` for managing restricted SFTP-only keys, and update `backtunnel-share` to support temporary accessor key authorization via `--allow-key` and `--allow-known`. Extend bash completion with profile, accessor, and SSH host suggestions. Revamp README sections to include updated workflows, quick starts, and key management details.
Add `backtunnel-open-term`, `backtunnel-share-tui`, and `backtunnel-access-tui` scripts for terminal-based interaction. Update Dolphin service menus to enable TUI workflows, with improved terminal detection logic. Enhance installation and uninstallation scripts to handle new files. Update README with terminal workflow details and logging information.
