graceful ctrl c interrupt handling

[AnthonyPFAVG]

Description (e.g. "Related to ...", etc.)

This PR adds graceful SIGINT (Ctrl+C) handling to update_repository. Updates can be interrupted safely without leaving repositories in a half-way/undefined state. Previously, a KeyboardInterrupt raised during update execution could cause undefined behavior. Now, the update_respository() function catches the interrupt, logs it, and raises an UpdateFailedError.

A new unit test, test_update_repository_interrupts_gracefully, simulates a (Ctrl+C) interrupt to verify this behavior.

Code review checklist (for code reviewer to complete)

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
• Title summarizes what is changing
• Commit messages are meaningful (see this for details)
• Tests have been included and/or updated, as appropriate
• Docstrings have been included and/or updated, as appropriate
• Changelog has been updated, as needed (see CHANGELOG.md)

[n-dusan]

Thanks for the contribution!

Before we can review this PR, we need to clarify a licensing point. To meet the needs of our government partners, we’re considering moving to a dual-license model (AGPL-3.0 / Apache-2.0) in the future.

Because of that, we need confirmation that your contribution can be relicensed under Apache 2.0 as part of this dual-license setup if/when it happens.

If that works for you, let us know and we'll proceed with review and merging. If not, that's totally fine, we'll close the PR.

Thanks for understanding.

[renatav]

Hi @AnthonyPFAVG, we've made it very easy to sign out Contributor License Agreement now. If you feel comfortable with that, we'll be happy to finally review and merge your PR. In any case, thanks for your interest in the project!

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}