Summary

• Add a regression test for partially answered multi-tool turns that later append the remaining real tool results.
• Add a regression test for dirty resume after truncated tool-call arguments, ensuring the repair is persisted via rewrite with the new turn.

Tests

• go test ./internal/agent -run 'TestSaveSnapshotAppendsAcrossPartiallyAnsweredMultiToolCallTail|TestSaveSnapshotAfterDirtyResumeWithTruncatedToolArgsPersistsRepair'\n- go test ./internal/agent\n- go test ./...\n- git diff --check\n\nFollow-up coverage for fix(agent): stop load-time repairs from masquerading as snapshot conflicts #6095.