Fix npc:nils → npc:nils-davan canonical ID mismatch. Replace
auto-flag gates on ring_completes/ring_splinters with player-
action-gated fact conditions (unreachable outcomes). Add
ring_stalemate terminal exit for non-terminal ring_splinters.
Create ring.yaml with 10 fact stubs for content/global/knowledge/.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>