Add automatic snapshot feature for QEMU VMs

[nesitor]

Create automatic Qemu snapshots every 10 minutes

Related ClickUp, GitHub or Jira tickets : ALEPH-XXX

Self proofreading checklist

• [X] The new code clear, easy to read and well commented.
• [X] New code does not duplicate the functions of builtin or popular libraries.
• [X] An LLM was used to review the new code and look for simplifications.
• [ ] New classes and functions contain docstrings explaining what they provide.
• [ ] All new code is covered by relevant tests.
• [ ] Documentation has been updated regarding these changes.
• [ ] Dependencies update in the project.toml have been mirrored in the Debian package build script packaging/Makefile

Changes

• Add automatic snapshots for QEMU VMs every 10 minutes by default
• Create QemuSnapshotManager to handle QEMU VM snapshot scheduling
• Implement create_snapshot method in AlephQemuInstance using QMP
• Keep only one active snapshot at a time, deleting previous ones
• Make QEMU confidential VMs also support snapshots
• Update pool and execution classes to use appropriate snapshot manager

🤖 Generated with Claude Code Co-Authored-By: Claude [email protected]

How to test

Check if a snapshot is created every 10 minutes