fix(external-cli): passthrough help and version flags

[chtangwin]

Summary

Forward --help and --version to external CLIs instead of handling them at the AutoCLI wrapper layer.

Problem

For external CLIs, commands like "--help", "--version" were intercepted by AutoCLI's wrapper parsing instead of reaching the underlying CLI directly.

$ gh --version
gh version 2.88.1 (2026-03-12)
https://github.com/cli/cli/releases/tag/v2.88.1

$ autocli --version
autocli 0.3.7

$ autocli gh --version
error: unexpected argument '--version' found

  tip: a similar argument exists: '--verbose'

Usage: autocli.exe gh --verbose

For more information, try '--help'.

$ gh --help
Work seamlessly with GitHub from the command line.

USAGE
  gh <command> <subcommand> [flags]

CORE COMMANDS
  auth:          Authenticate gh and git with GitHub
...

$ autocli gh --help
GitHub CLI — repos, PRs, issues, releases, gists

Usage: autocli.exe gh [OPTIONS] [COMMAND]

Options:
  -f, --format <format>  Output format: table, json, yaml, csv, md [default: table]
  -v, --verbose          Enable verbose output
  -h, --help             Print help

$ autocli --help
AI-driven CLI tool — turns websites into command-line interfaces

Usage: autocli.exe [OPTIONS] [COMMAND]

Commands:
  antigravity
  apple-podcasts
  arxiv
...

Changes

• disable wrapper-level --help handling for external CLI subcommands
• disable wrapper-level --version handling for external CLI subcommands
• pass trailing args through directly to the external binary

Result

External CLIs now behave more like native commands and align better with user and agent expectations.

$ autocli --version
autocli 0.3.7

$ autocli gh --version
gh version 2.88.1 (2026-03-12)
https://github.com/cli/cli/releases/tag/v2.88.1

$ gh --version
gh version 2.88.1 (2026-03-12)
https://github.com/cli/cli/releases/tag/v2.88.1

$ autocli --help
AI-driven CLI tool — turns websites into command-line interfaces

Usage: autocli.exe [OPTIONS] [COMMAND]

Commands:
  antigravity
  apple-podcasts
  arxiv
...

$ autocli gh --help
Work seamlessly with GitHub from the command line.

USAGE
  gh <command> <subcommand> [flags]

CORE COMMANDS
  auth:          Authenticate gh and git with GitHub
...