Maintenance sweep: archived / stale entries to review

.venv/bin/python scripts/check_unmaintained.py
## Unmaintained-entry sweep

_As of 2026-08-03; stale threshold = 9.0 months. This is a review aid — entries are NOT auto-removed (R-RF-4)._

### Archived upstream (0)
- none

### Possibly stale (0)
- none

### Unknown activity (needs a metadata refresh) (0)
- none

