Add help text to all hook CLI arguments

[shenxianpeng]

Context

The argparse definitions in the hook wrappers are inconsistent: some arguments have a help= description and others don't. For example, --fix in clang_tidy.py has help text, but --version, --compile-commands, --no-compile-commands, -j/--jobs, and -v/--verbose do not. This makes -h output incomplete and the code a little harder to read for newcomers.

Task

Add a short, one-line help= string to every add_argument(...) call that lacks one, in both files.

Files

• cpp_linter_hooks/clang_format.py — --version
• cpp_linter_hooks/clang_tidy.py — --version, --compile-commands, --no-compile-commands, -j/--jobs, -v/--verbose

Suggested wording (feel free to refine):

• --version: "Version of the clang tool to install/run (e.g. 21 or 21.1.0); defaults to the latest stable wheel on PyPI."
• --compile-commands: "Directory containing compile_commands.json to pass to clang-tidy via -p."
• --no-compile-commands: "Disable auto-detection of compile_commands.json."
• -j/--jobs: "Number of clang-tidy processes to run in parallel (default: 1)."
• -v/--verbose: "Enable verbose output."

Acceptance criteria

• Every add_argument in both files has a help= string.
• No behavior change; existing tests still pass (pytest).

Getting started

See CONTRIBUTING.md. This is a docs/readability-only change — no logic is affected.