fix(simulation): review fixes — walk-away source and Loyal trait filter

record_incomplete_interaction now uses Heard/Close source instead of
DirectObservation, preventing false inoculation against contradiction
detection. Wired exclude_high_trust_entities (Loyal trait) filter into
derive_disclosure_candidates — facts from Friendly-relationship source
entities are excluded from disclosure pool.

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

server/src/knowledge/graph.rs

@@ -210,7 +210,14 @@ impl KnowledgeGraph {
                 last_observed_tick: 0,
                 last_updated_tick: 0,
                 confidence: KnowledgeConfidence::Suspects,
-                source: KnowledgeSource::DirectObservation { tick },
+                // Heard/Close — not DirectObservation, because walk-away is
+                // not a confirmed sighting. Using DirectObservation here
+                // would falsely inoculate the entry against contradiction
+                // detection (pre-overwrite check only fires on ToldBy source).
+                source: KnowledgeSource::Heard {
+                    tick,
+                    range: super::types::SoundRange::Close,
+                },
                 state: KnowledgeState::Active,
                 relationship: RelationshipState::Unknown,
                 known_attributes: BTreeMap::new(),