feat: show subcommands after hostnames in shell completion

Use ShellCompDirectiveKeepOrder so fish/zsh/bash preserve the returned
order instead of sorting alphabetically. ValidArgsFunction now appends
subcommand names (with their short descriptions) after all hostname
entries, so hosts always appear first in the completion list.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmd/netssh/main.go

@@ -199,18 +199,25 @@ func rootCmd() *cobra.Command {
 			}
 			c := cache.New(cfg.Cache.Path, cfg.Cache.TTL)
 			_ = c.Load()
-			entries := c.Search(toComplete)
-			names := make([]cobra.Completion, len(entries))
-			for i, e := range entries {
-				names[i] = cobra.Completion(e.Name)
+
+			var completions []cobra.Completion
+			for _, e := range c.Search(toComplete) {
+				completions = append(completions, cobra.Completion(e.Name))
 			}
-			return names, cobra.ShellCompDirectiveNoFileComp
+			// Subcommands at the end, after all hostnames.
+			for _, sub := range cmd.Commands() {
+				if sub.IsAvailableCommand() && strings.HasPrefix(sub.Name(), toComplete) {
+					completions = append(completions, cobra.Completion(sub.Name()+"\t"+sub.Short))
+				}
+			}
+			return completions, cobra.ShellCompDirectiveNoFileComp | cobra.ShellCompDirectiveKeepOrder
 		},
 	}
 
-	// cobra automatically adds a "completion" subcommand; we extend it with "install".
 	root.AddCommand(configureCmd(), searchCmd(), cacheCmd())
 
+	// cobra builds the "completion" command lazily; force init so we can extend it.
+	root.InitDefaultCompletionCmd()
 	for _, cmd := range root.Commands() {
 		if cmd.Name() == "completion" {
 			cmd.AddCommand(completionInstallCmd(root))
@@ -244,7 +251,8 @@ func completionInstallCmd(root *cobra.Command) *cobra.Command {
 				file = filepath.Join(dir, "netssh")
 				gen = func() ([]byte, error) {
 					var buf strings.Builder
-					return []byte(buf.String()), root.GenBashCompletionV2(&buf, true)
+					err := root.GenBashCompletionV2(&buf, true)
+					return []byte(buf.String()), err
 				}
 				note = "Reload your shell or run: source " + file
 			case "zsh":
@@ -252,7 +260,8 @@ func completionInstallCmd(root *cobra.Command) *cobra.Command {
 				file = filepath.Join(dir, "_netssh")
 				gen = func() ([]byte, error) {
 					var buf strings.Builder
-					return []byte(buf.String()), root.GenZshCompletion(&buf)
+					err := root.GenZshCompletion(&buf)
+					return []byte(buf.String()), err
 				}
 				note = "Make sure ~/.zfunc is in your fpath:\n  fpath=(~/.zfunc $fpath)\n  autoload -Uz compinit && compinit"
 			case "fish":
@@ -261,7 +270,8 @@ func completionInstallCmd(root *cobra.Command) *cobra.Command {
 				file = filepath.Join(dir, "netssh.fish")
 				gen = func() ([]byte, error) {
 					var buf strings.Builder
-					return []byte(buf.String()), root.GenFishCompletion(&buf, true)
+					err := root.GenFishCompletion(&buf, true)
+					return []byte(buf.String()), err
 				}
 				note = "Reload your shell or start a new fish session."
 			default: