Integration testing for Ink TUI

[randomm]

Phase 3 of Ink TUI Rewrite

Objective

Comprehensive testing of concurrent scenarios that caused issues in previous implementation.

Critical Test Scenarios

• Prose streaming + tool status updates simultaneously
• Multiple tools running in parallel
• Task with child tool + prose streaming
• Child session event buffering
• Cancel during streaming
• Terminal resize during operation

Tasks

• Create test fixtures for SDK events
• Write concurrent update tests
• Write child session event tests
• Write message lifecycle tests
• Manual testing checklist

Acceptance Criteria

• All automated tests pass
• No crashes in normal usage
• No crashes in edge cases

Estimated: 3.5 days

[randomm]

Completed - Integration tests added (234 tests passing)