feat: fn check params y fn show muestra params_schema

Nuevo subcomando 'fn check params' lista funciones sin params_schema documentado.
'fn show' ahora muestra el campo Params con el JSON semántico de inputs/outputs.

cmd/fn/main.go

@@ -35,6 +35,8 @@ func main() {
 		cmdProposal(os.Args[2:])
 	case "run":
 		cmdRun(os.Args[2:])
+	case "check":
+		cmdCheck(os.Args[2:])
 	case "app":
 		cmdApp(os.Args[2:])
 	case "analysis":
@@ -58,6 +60,7 @@ Usage:
   fn show   <id>                           Muestra entrada completa
   fn add    [-k kind]                      Abre $EDITOR con template
   fn run    <id_or_name> [args...]          Ejecuta funcion/pipeline (go/py/bash)
+  fn check  params                          Lista funciones sin params_schema
   fn ops    <subcommand>                   Gestiona operations.db (fn ops help)
   fn proposal <add|list|show|update>       Gestiona proposals
   fn app     <list|clone|pull>             Gestiona apps externas (Gitea)
@@ -387,6 +390,9 @@ func printFunction(f *registry.Function) {
 	if len(f.Imports) > 0 {
 		fmt.Printf("Imports:     %s\n", strings.Join(f.Imports, ", "))
 	}
+	if f.ParamsSchema != "" {
+		fmt.Printf("Params:      %s\n", f.ParamsSchema)
+	}
 	if f.Example != "" {
 		fmt.Printf("\nExample:\n%s\n", f.Example)
 	}
@@ -512,6 +518,53 @@ func printAnalysisEntry(a *registry.Analysis) {
 	}
 }
 
+// --- check ---
+
+func cmdCheck(args []string) {
+	if len(args) < 1 {
+		fmt.Fprintln(os.Stderr, "usage: fn check <subcommand>\n\nSubcommands:\n  params    Lista funciones sin params_schema documentado")
+		os.Exit(1)
+	}
+	switch args[0] {
+	case "params":
+		cmdCheckParams()
+	default:
+		fmt.Fprintf(os.Stderr, "unknown check subcommand: %s\n", args[0])
+		os.Exit(1)
+	}
+}
+
+func cmdCheckParams() {
+	db := openDB()
+	defer db.Close()
+
+	fns, err := db.SearchFunctions("", "", "", "", "")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
+
+	var missing []registry.Function
+	for _, f := range fns {
+		if f.ParamsSchema == "" {
+			missing = append(missing, f)
+		}
+	}
+
+	if len(missing) == 0 {
+		fmt.Printf("All %d functions have params_schema documented.\n", len(fns))
+		return
+	}
+
+	fmt.Printf("%d/%d functions missing params_schema:\n\n", len(missing), len(fns))
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
+	fmt.Fprintln(w, "ID\tLANG\tDOMAIN\tKIND")
+	for _, f := range missing {
+		fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", f.ID, f.Lang, f.Domain, f.Kind)
+	}
+	w.Flush()
+}
+
 // --- add ---
 
 func cmdAdd(args []string) {