Implement RefineExternalitiesImpl

[coderabbitai]

Follow-up task from PR #859: #859

Machine-related work to be split into multiple PRs.

Currently, RefineExternalitiesImpl is a stub implementation with all methods throwing "Method not implemented." errors. This task involves implementing the actual machine-level operations including:

• Machine expunge, pages management, void/zero pages
• Memory peek/poke operations
• Machine initialization and invocation
• Segment export
• Historical lookups

Each point should be handled separately as a sub-task.

Requested by: @tomusdrw
Reference: #859 (comment)