Bump pinned @coana-tech/cli to 15.12.1

[socket-pr-bot]

Summary

• Bumps the pinned reachability engine @coana-tech/cli from 15.11.6 to 15.12.1 and bumps the Python CLI version to 2.10.9.
• This PR was created automatically by a bot.

Engine changelog

For what is included in this engine release, see the reachability analysis changelog.

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Note

Low Risk
Routine pinned-engine and semver bump with no application logic changes; reachability results may differ only due to the upstream Coana engine version.

Overview
Releases Socket Python CLI 2.10.9 and updates the default reachability engine from @coana-tech/cli 15.11.6 to 15.12.1.

The pinned version in DEFAULT_COANA_CLI_VERSION (reachability.py) is what runs when --reach is used without --reach-version. CHANGELOG and cli-reference document the new default; pyproject.toml, __init__.py, and uv.lock carry the package version bump.

Engine behavior changes for 15.12.1 are documented in the reachability analysis changelog; this PR does not change CLI reachability logic beyond the pin.

^{Reviewed by Cursor Bugbot for commit 9f0883b. Configure here.}