FN-6220: harden AI merge worktree cleanup
Harden AI merge cleanup so temporary clean-room worktrees are removed and audited reliably.
- Canonicalize AI merge cleanup paths and prune stale git worktree metadata after removals.
- Treat already-absent or de-registered cleanup paths as idempotent success while still auditing genuine failures.
- Add regression coverage for successful, no-op, retry, thrown, orphaned, and dangling-registration cleanup paths.
- Document the inline and self-healing cleanup lifecycle for AI merge temp worktrees.
Files changed:
docs/architecture.md | 4 +-
.../engine/src/__tests__/merger-ai-cleanup.test.ts | 28 +-
.../ai-merge-worktree-cleanup.test.ts | 284 +++++++++++++++++++++
packages/engine/src/merger-ai.ts | 108 +++++---
4 files changed, 392 insertions(+), 32 deletions(-)
Fusion-Task-Id: FN-6220
Fusion-Task-Lineage: b002313c-4349-49c2-8d0f-cd1853369d84