Add a background thread fetching guest logs periodically

[happz]

Pull Request Checklist

• implement the feature
• write the documentation
• extend the test coverage
• update the specification
• adjust plugin docstring
• modify the json schema
• mention the version
• include a release note

[gemini-code-assist]

Code Review

This pull request introduces a background thread GuestLogUpdater to periodically update guest logs, along with kickoff_logs and finalize_logs methods to manage the log collection lifecycle. Replace threading.Condition and threading.Event in GuestLogUpdater with a single threading.Event to prevent a runtime RuntimeError. Call self.finalize_logs(logger=logger) in the stop methods of the local and mock provision plugins to ensure guest logs are properly finalized and torn down.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.