## Summary
- fail closed when a persisted external remediation route lacks a
concrete checkout path
- verify recovery, remediation, dependency-abort cleanup, and completion
validation use the live persisted task route
- use unique missing-checkout fixtures and exact observed-path
assertions
## Test plan
- `pnpm --filter @fusion/engine exec vitest run
src/__tests__/verify-worktree-invariants-missing.test.ts
src/__tests__/executor-triage-column-audit.test.ts --silent=passed-only
--reporter=dot`
- `pnpm --filter @fusion/engine exec vitest run
src/__tests__/executor-fast-mode-workflows.test.ts -t 'completed-task
recovery captures the live external checkout|pre-merge remediation'
--silent=passed-only --reporter=dot`
- `pnpm --filter @fusion/engine typecheck`
- `pnpm exec eslint packages/engine/src/executor.ts
packages/engine/src/__tests__/verify-worktree-invariants-missing.test.ts
packages/engine/src/__tests__/executor-triage-column-audit.test.ts
packages/engine/src/__tests__/executor-fast-mode-workflows.test.ts`
- `pnpm check:fnxc-future-dates`
- `pnpm check:changesets --strict`
- `git diff --check`
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Bug Fixes**
* Improved recovery for externally executed tasks by using the latest
routing information instead of outdated task data.
* External remediation now stops safely when a checkout location is
missing or invalid, preventing execution in an unintended location.
* Improved cleanup behavior to preserve operator-owned checkouts.
* Enhanced validation and error reporting for missing or invalid
checkout paths.
* **Tests**
* Expanded coverage for recovery, remediation safety, checkout
ownership, and worktree validation scenarios.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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