## Description
This pull request adds a new tool, cloud-sql-restore-backup, which
enables restoring a backup onto a Cloud SQL instance from the toolbox
using the Cloud SQL Admin API. The tool supports restoring standard,
project level, and BackupDR backups.
Tested:
<img width="3758" height="532" alt="image"
src="https://github.com/user-attachments/assets/d1d61af7-d96e-417c-898c-65b876de4c5e"
/>
## PR Checklist
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [x] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [x] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [x] Ensure the tests and linter pass
- [x] Code coverage does not decrease (if any source code was changed)
- [x] Appropriate docs were updated (if necessary)
- [x] Make sure to add `!` if this involve a breaking change
🛠️Fixes#2170
Co-authored-by: Averi Kitsch <akitsch@google.com>
