feat: print command errors via hook

this allows users to remove the handlers and print
a custom message to their liking

exec.go

@@ -141,9 +141,9 @@ func runInput(input string, priv bool) {
 	if err != nil {
 		if exErr, ok := isExecError(err); ok {
 			hooks.Emit("command." + exErr.typ, exErr.cmd)
-			err = exErr.sprint()
+		} else {
+			fmt.Fprintln(os.Stderr, err)
 		}
-		fmt.Fprintln(os.Stderr, err)
 	}
 	cmdFinish(exitCode, input, priv)
 }

nature/init.lua

@@ -69,3 +69,11 @@ end
 bait.catch('error', function(event, handler, err)
 	bait.release(event, handler)
 end)
+
+bait.catch('command.not-found', function(cmd)
+	print(string.format('hilbish: %s not found', cmd))
+end)
+
+bait.catch('command.not-executable', function(cmd)
+	print(string.format('hilbish: %s: not executable', cmd))
+end)