[10kartik]

What type of PR is this?

• bug

What this PR does / why we need it:

app help foo bar shows the help of foo, not of its subcommand bar, and silently ignores bar. The same goes for app -h foo bar. Only app foo help bar reaches bar:

cmd := &cli.Command{
	Name: "app",
	Commands: []*cli.Command{
		{Name: "cmd", Commands: []*cli.Command{{Name: "subcmd", Usage: "runs subcmd"}}},
	},
}

$ app help cmd subcmd
NAME:
   app cmd - ...        <- cmd's help, not subcmd's

helpCommandAction only looked at the first arg. It now follows the args down as long as each one names a subcommand of the previous one, aliases included, and shows the help of the last match. An arg that isn't a subcommand stops the walk, so app help cmd nope still shows cmd's help, as it does today.

Which issue(s) this PR fixes:

None, found while checking help output for nested commands.

Testing

• New TestHelpCommand_NestedPath covers help cmd subcmd, an alias in the path, -h cmd subcmd, and help cmd nope. The first three fail on main; the last passes before and after.
• make generate vet check-binary-size and make v3diff pass, with no API change. go test -race ./... passes, as do the tests with urfave_cli_no_template, urfave_cli_no_docs and urfave_cli_no_suggest.

The change and the test were written with Claude Code (AI).

Release Notes

`help` and `--help` now show the help of the last subcommand in a path such as `app help foo bar`, instead of stopping at the first.

🤖 Generated with Claude Code

[coilysiren]

LGTM