[engine-failure] PROJ-859-llmxive-follow-up-extending-memslides-a @ tasks: RuntimeError

Automated report (spec 023 / FR-016) — an unexpected engine failure occurred while processing **PROJ-859-llmxive-follow-up-extending-memslides-a** at stage `tasks`.

```
RuntimeError: LLMReviewer[coverage]: review frontmatter has neither `verdict:` nor `concerns:`/`action_items:` — a contentless/truncated review MUST NOT count as acceptance (false-convergence guard). First 200 chars: '```yaml\n---\nreviewer_name: coverage\nreviewer_kind: llm\nstage: tasked\nartifact_path: projects/PROJ-859-llmxive-follow-up-extending-memslides-a/specs/001-llmxive-follow-up-extending-memslides-a/tasks.md'
```

The project remains schedulable; it will retry on its normal cadence and recover once the underlying defect is fixed. Closing this issue does not require any project-state change.

Start with the LLMReviewer coverage-stage handling for projects/PROJ-859-llmxive-follow-up-extending-memslides-a/specs/001-llmxive-follow-up-extending-memslides-a/tasks.md and trace how its review frontmatter is parsed. Reproduce the reported RuntimeError with the truncated review shown in the issue; done means a contentless review cannot count as acceptance and the project remains retryable on its normal cadence.

Written by the indexing model from the issue text.