Replace PLACEHOLDER stubs with full prose for: Fenwick's Lantern (GJ-285), Dunmore Stillwater (GJ-300), Uusi Vantaa (GJ-3820), Harrowfield (GJ-588), Kelburn Crossing (GJ-216A), Greymantle (GJ-638). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>