fix: restore --help on every subcommand

[ColeMei]

openwith set --help, openwith history --help — and the same for every other subcommand, with -h too — failed with error: unexpected argument '--help' found (exit 2).

Cause

disable_help_flag = true on the root Cli propagates to every subcommand in clap v4. The manual field beneath it put -h/--help back only at the root:

#[arg(short = 'h', long = "help", action = clap::ArgAction::HelpLong)]
pub help: (),

So subcommands had the flag disabled with nothing restoring it. openwith --help kept rendering the logo screen the whole time, which is why this survived since the custom help template was introduced.

Fix

Drop disable_help_flag and the manual field, and set the logo help_template on the root command only. Subcommands fall back to clap's generated help, which lists their real flags:

Usage: openwith history [OPTIONS]

Options:
  -n, --limit <LIMIT>  Maximum number of events to show [default: 20]
  -d, --days <DAYS>    Only show events from the last N days [default: 7]
      --all            Show every retained event, ignoring --days
      --json           Print JSON

disable_version_flag and its manual field stay — --version belongs to the root alone and was never affected.

Verified

• Root --help and -h still render the ASCII-logo template
• --version / -v unchanged
• All 9 subcommands accept both --help and -h
• openwith help <sub> works as well
• completions (zsh/bash/fish) and mangen still produce output — the Homebrew formula calls both during install
• Normal operation (current, history) unaffected

Two tests added. every_subcommand_accepts_help is a genuine guard: it was confirmed to fail against the old definition (`openwith list` has no --help flag) and pass against the fix.

Not tagging a release for this — it'll ride along with the next batch of changes.