feat(simulation): knowledge grant schema, events, and contradiction detection (#545, #546, #547)

KnowledgeGrant untagged enum (Fact + Entity variants), ContentEntityRegistry
resource, KnowledgeGranted event processing, ContradictionClaim struct with
600-tick window detection in observe_entity. Wires knowledge_grant field in
dialogue line selection. Implements D-079, D-083. Closes Q-026.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/tests/content_loading.rs

@@ -214,6 +214,7 @@ fn verify_template_role_slots() {
 fn spawn_npc_from_content_store() {
     let mut world = World::new();
     world.init_resource::<EntityRegistry>();
+    world.init_resource::<settled_reach_server::knowledge::ContentEntityRegistry>();
 
     // Create a minimal content store with one test NPC
     let mut store = ContentStore::default();
@@ -333,6 +334,7 @@ fn spawn_real_content_with_relationships_and_secrets() {
 
     let mut world = World::new();
     world.init_resource::<EntityRegistry>();
+    world.init_resource::<settled_reach_server::knowledge::ContentEntityRegistry>();
     world.init_resource::<settled_reach_server::npc::relationships::RelationshipGraph>();
 
     let store = load_content(&root).expect("content loading should succeed");