Reconciliation commit and canonical world update

[theinterneti]

Part of #270

Apply resolved states to main branch via DOLT_COMMIT. Write narrative descriptions as WorldEvent nodes in Neo4j. Publish WorldChangeEvents to Redis pub/sub for affected players.

Acceptance Criteria

• Resolved states applied to main branch via DOLT_COMMIT('reconciliation: session {id}')
• Each resolution written as (WorldEvent) node in Neo4j with narrative_description
• WorldChangeEvent published to Redis channel 'world_changes:{world_id}'
• Affected players' sessions receive change notification via SSE
• Integration test: full reconciliation flow from conflict detection to player notification