Add termscp - comprehensive CLI-UI FTP tool

- Add termscp package to home.packages in flake.nix
- Add 'ftp' alias pointing to termscp in zsh.nix
- Update README.md with termscp documentation and usage examples
- Provides rich TUI for FTP/SFTP/SCP/S3/WebDAV file transfers
- Complements existing lftp for scripting vs interactive use

Key features:
- Multi-protocol support (FTP, SFTP, SCP, S3, WebDAV)
- Interactive dual-pane file browser
- Bookmarks and connection management
- File synchronization capabilities
- Customizable themes and interface

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

modules/zsh.nix

@@ -33,6 +33,9 @@ in
       gl = "git pull";
       gd = "git diff";
       
+      # Modern CLI tools
+      ftp = "termscp";
+      
       # Nix helpers
       hm = "home-manager";
       hms = "home-manager switch --flake ~/.config/nix#yanlin";