Improve structured event capture for errors and test runs

[bme2003]

Summary

Terminal commands are captured today, but errors and tests should be represented more explicitly.

Proposed Change

• Add helper CLI commands for test results and error events
• Store status, command, summary, and excerpt
• Surface them in resume and handoff output

Acceptance Criteria

• Tests can be recorded as structured events
• Errors can be recorded as structured events
• Resume/handoff highlights recent failures cleanly

[IlyasFardaouix]

I think the root cause of the issue might be that the event_type enum in 0001_initial_schema.py is missing one of the event types mentioned in the proposed change (test result, error). Can you confirm if this is the intended enum?