Handle Click exceptions by hand

[rolandwalker]

Description

Handle Click exceptions by hand, creating a main() function which handles Click's exceptions and returns an integer, or exits.

Per the documentation at

• https://click.palletsprojects.com/en/stable/exceptions/

we need to catch click.Abort and click.ClickException, but BrokenPipeError was also added.

Recast the cli() function as click_entrypoint() to help differentiate it from run_cli(). The latter one could even be renamed to run_repl()!

Motivation: prompt_toolkit is already handling exceptions such as KeyboardInterrupt. We had two layers trying to handle exceptions transparently, and we want control-c to cancel pending queries very reliably. Let's start to untangle.

This also exposes the arguments to be processed by Click, which is desirable in case we want to pre-process them. Example: mycli -h could print the helpdoc, instead of being interpreted as a missing hostname. Example: we could catch some issues with --password before running Click.

Checklist

• I added this contribution to the changelog.md file.
• I added my name to the AUTHORS file (or it's already there).
• To lint and format the code, I ran

  uv run ruff check && uv run ruff format && uv run mypy --install-types .

[github-actions]

I can’t complete a real review yet because I can’t read the repo in this session: all shell commands fail with bwrap: loopback: Failed RTM_NEWADDR: Operation not permitted.

Please paste one of these, and I’ll review immediately:

1. git diff --unified=3 77a3fe5d7f8b1a1814c9ab4e4b30cab535959a6e...b3bdb16f1acef1b1e8b7307caf527a03ec9e618d
2. Or the changed files’ patches from PR Handle Click exceptions by hand #1714.

Once you share that, I’ll return concise findings focused on correctness regressions, security, and missing tests/edge cases only.