feat(configure): edit every config option in the configurator

After the NetBox instances, netssh configure now opens a menu with all
sections: SSH defaults, global SSH options (jump host, host key
checking, target, address family, extra args, -o options), SSH rules,
resolver & cache (including the cache file), shortcuts & command alias,
and completion.max_results. SSH options can also be set per instance.

The wizard rebuilt the config from its own fields, so re-running it
dropped global SSH options, ssh.rules and completion.max_results from
the file. It now edits a copy of the loaded config, and save validates
SSH options and rules before writing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/setup/instances.go

@@ -30,6 +30,7 @@ func configureInstances(cfg *config.Config) ([]config.NetBoxConfig, error) {
 		var options []huh.Option[string]
 		for _, source := range sources {
 			options = append(options, huh.NewOption("Edit "+source.Name+" ("+source.URL+")", "edit:"+source.Name))
+			options = append(options, huh.NewOption("SSH options for "+source.Name, "ssh:"+source.Name))
 			options = append(options, huh.NewOption("Remove "+source.Name, "remove:"+source.Name))
 		}
 		options = append(options, huh.NewOption("Add another NetBox", "add"), huh.NewOption("Continue with these instances", "done"))
@@ -53,13 +54,20 @@ func configureInstances(cfg *config.Config) ([]config.NetBoxConfig, error) {
 			if source.Name != name {
 				continue
 			}
-			if verb == "edit" {
+			switch verb {
+			case "edit":
 				edited, err := editInstance(source, sources, name)
 				if err != nil {
 					return nil, err
 				}
 				sources[i] = edited
-			} else {
+			case "ssh":
+				options, err := editSSHOptions("SSH options for "+name, source.SSH)
+				if err != nil {
+					return nil, err
+				}
+				sources[i].SSH = options
+			default:
 				remove := false
 				if err := huh.NewConfirm().Title("Remove " + name + "?").Value(&remove).Run(); err != nil {
 					return nil, err