feat(perception): add cognitive delay system for fog recognition (#423)

New CognitiveDelay component buffers perception events before emitting
KnowledgeEvents. Normal delay: 6 ticks (0.6s), urgent: 3 ticks (0.3s).
Drain system runs after emit_observation_events, before process_knowledge_events.

Adds pending_recognitions to ObserverSnapshot (protocol v7) for client
fog entity visualization. Includes cancellation when entity leaves LOS.

Monologue fires during delay (not after) per D-060 — cross-system
wiring deferred to follow-up ticket #451.

Ref: D-060 (cognitive delay), D-031 (10 tps), D-059 (fog layers)

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

server/tests/bridge_ipc.rs

@@ -57,6 +57,7 @@ fn snapshot_roundtrip_over_unix_socket() {
             visible_tiles: vec![],
             nearby_interactions: vec![],
             current_monologue: None,
+            pending_recognitions: vec![],
         };
 
         bridge
@@ -119,7 +120,10 @@ fn input_roundtrip_over_unix_socket() {
         },
         PlayerInput {
             tick: 11,
-            action: PlayerAction::Interact { target_entity_id: None, verb: None },
+            action: PlayerAction::Interact {
+                target_entity_id: None,
+                verb: None,
+            },
         },
     ];
 

server/tests/bridge_tcp.rs

@@ -43,6 +43,7 @@ fn snapshot_roundtrip_over_tcp() {
             visible_tiles: vec![],
             nearby_interactions: vec![],
             current_monologue: None,
+            pending_recognitions: vec![],
         };
 
         bridge
@@ -98,7 +99,10 @@ fn input_roundtrip_over_tcp() {
         },
         PlayerInput {
             tick: 11,
-            action: PlayerAction::Interact { target_entity_id: None, verb: None },
+            action: PlayerAction::Interact {
+                target_entity_id: None,
+                verb: None,
+            },
         },
     ];
 

server/tests/gen_fixtures.rs

@@ -33,6 +33,7 @@ fn fixture_snapshot(tick: u64, entities: Vec<VisibleEntity>) -> ObserverSnapshot
         visible_tiles: vec![],
         nearby_interactions: vec![],
         current_monologue: None,
+        pending_recognitions: vec![],
     }
 }
 
@@ -200,6 +201,7 @@ fn generate_msgpack_fixtures() {
         ],
         nearby_interactions: vec![],
         current_monologue: None,
+        pending_recognitions: vec![],
     };
     write_fixture(
         "snapshot_v2_full",
@@ -214,7 +216,10 @@ fn generate_msgpack_fixtures() {
         },
         PlayerInput {
             tick: 0,
-            action: PlayerAction::Interact { target_entity_id: None, verb: None },
+            action: PlayerAction::Interact {
+                target_entity_id: None,
+                verb: None,
+            },
         },
     ];
     write_fixture(

server/tests/serialization.rs

@@ -22,6 +22,7 @@ fn test_snapshot(tick: u64, entities: Vec<VisibleEntity>) -> ObserverSnapshot {
         visible_tiles: vec![],
         nearby_interactions: vec![],
         current_monologue: None,
+        pending_recognitions: vec![],
     }
 }
 
@@ -86,7 +87,10 @@ fn all_player_action_variants_roundtrip() {
         PlayerAction::MoveNorthwest,
         PlayerAction::MoveSoutheast,
         PlayerAction::MoveSouthwest,
-        PlayerAction::Interact { target_entity_id: None, verb: None },
+        PlayerAction::Interact {
+            target_entity_id: None,
+            verb: None,
+        },
         PlayerAction::UsePerceptionMode("thermal".to_string()),
         PlayerAction::Pause,
         PlayerAction::Unpause,
@@ -134,7 +138,11 @@ fn all_fixtures_deserialize() {
         if name.starts_with("snapshot") {
             let snap = rmp_serde::from_slice::<ObserverSnapshot>(&bytes)
                 .unwrap_or_else(|e| panic!("deserialize snapshot fixture {}: {}", name, e));
-            assert_eq!(snap.version, PROTOCOL_VERSION, "fixture {} has wrong version", name);
+            assert_eq!(
+                snap.version, PROTOCOL_VERSION,
+                "fixture {} has wrong version",
+                name
+            );
         } else if name.starts_with("input_batch") {
             rmp_serde::from_slice::<Vec<PlayerInput>>(&bytes)
                 .unwrap_or_else(|e| panic!("deserialize batch input fixture {}: {}", name, e));
@@ -225,6 +233,7 @@ fn snapshot_v2_fields_roundtrip() {
         ],
         nearby_interactions: vec![],
         current_monologue: None,
+        pending_recognitions: vec![],
     };
 
     let bytes = rmp_serde::to_vec_named(&snapshot).expect("serialize");
@@ -237,8 +246,14 @@ fn snapshot_v2_fields_roundtrip() {
     assert_eq!(decoded.game_time.tick_rate, TickRate::Paused);
     assert_eq!(decoded.player_facing, FacingDirection::Southeast);
     assert_eq!(decoded.visible_tiles.len(), 2);
-    assert_eq!(decoded.visible_tiles[0].visibility, VisibilitySector::Forward);
-    assert_eq!(decoded.visible_tiles[1].visibility, VisibilitySector::Peripheral);
+    assert_eq!(
+        decoded.visible_tiles[0].visibility,
+        VisibilitySector::Forward
+    );
+    assert_eq!(
+        decoded.visible_tiles[1].visibility,
+        VisibilitySector::Peripheral
+    );
     assert_eq!(decoded.entities[0].visibility, VisibilitySector::Forward);
 }
 
@@ -259,7 +274,11 @@ fn entity_to_bits_roundtrip() {
     for entity in [e1, e2, e3, e4] {
         let bits = entity.to_bits();
         let restored = Entity::from_bits(bits);
-        assert_eq!(entity, restored, "Entity::to_bits() roundtrip failed for {:?}", entity);
+        assert_eq!(
+            entity, restored,
+            "Entity::to_bits() roundtrip failed for {:?}",
+            entity
+        );
     }
 }
 
@@ -268,7 +287,10 @@ fn entity_to_bits_roundtrip() {
 fn protocol_version_constant_matches_snapshot() {
     let snapshot = test_snapshot(0, vec![]);
     assert_eq!(snapshot.version, PROTOCOL_VERSION);
-    assert_eq!(PROTOCOL_VERSION, 6, "bump this assertion when protocol version changes");
+    assert_eq!(
+        PROTOCOL_VERSION, 7,
+        "bump this assertion when protocol version changes"
+    );
 }
 
 /// All FacingDirection variants round-trip
@@ -302,6 +324,7 @@ fn all_facing_direction_variants_roundtrip() {
             visible_tiles: vec![],
             nearby_interactions: vec![],
             current_monologue: None,
+            pending_recognitions: vec![],
         };
         let bytes = rmp_serde::to_vec_named(&snapshot).expect("serialize");
         let decoded: ObserverSnapshot = rmp_serde::from_slice(&bytes).expect("deserialize");
@@ -412,19 +435,35 @@ fn v5_payload_deserializes_into_v6_struct() {
     // New fields should get their defaults
     assert_eq!(decoded.version, 5, "version field preserved from v5");
     assert_eq!(decoded.tick, 42);
-    assert_eq!(decoded.player_stance, MovementStance::Walk, "missing stance should default to Walk");
-    assert!(decoded.player_inventory.is_empty(), "missing inventory should default to empty");
-    assert!(decoded.current_monologue.is_none(), "missing monologue should default to None");
+    assert_eq!(
+        decoded.player_stance,
+        MovementStance::Walk,
+        "missing stance should default to Walk"
+    );
+    assert!(
+        decoded.player_inventory.is_empty(),
+        "missing inventory should default to empty"
+    );
+    assert!(
+        decoded.current_monologue.is_none(),
+        "missing monologue should default to None"
+    );
+    assert!(
+        decoded.pending_recognitions.is_empty(),
+        "missing pending_recognitions should default to empty"
+    );
 }
 
 /// Full 9-slot inventory roundtrip (D-065: 3x3 grid = 9 slots universal)
 #[test]
 fn snapshot_v6_full_inventory_roundtrip() {
-    let items: Vec<InventoryItem> = (0..9).map(|i| InventoryItem {
-        item_id: 100 + i as u64,
-        name: format!("Item {}", i),
-        slot: i,
-    }).collect();
+    let items: Vec<InventoryItem> = (0..9)
+        .map(|i| InventoryItem {
+            item_id: 100 + i as u64,
+            name: format!("Item {}", i),
+            slot: i,
+        })
+        .collect();
 
     let mut snapshot = test_snapshot(0, vec![]);
     snapshot.player_inventory = items;
@@ -482,7 +521,8 @@ fn all_verb_kind_variants_roundtrip() {
         assert_eq!(decoded.nearby_interactions.len(), 1);
         assert_eq!(
             decoded.nearby_interactions[0].verbs[0].kind, kind,
-            "VerbKind::{:?} did not roundtrip", kind
+            "VerbKind::{:?} did not roundtrip",
+            kind
         );
     }
 }
@@ -506,7 +546,11 @@ fn all_object_type_variants_roundtrip() {
     for obj_type in types {
         let bytes = rmp_serde::to_vec_named(&obj_type).expect("serialize");
         let decoded: ObjectType = rmp_serde::from_slice(&bytes).expect("deserialize");
-        assert_eq!(decoded, obj_type, "ObjectType::{:?} roundtrip failed", obj_type);
+        assert_eq!(
+            decoded, obj_type,
+            "ObjectType::{:?} roundtrip failed",
+            obj_type
+        );
     }
 }
 
@@ -533,7 +577,10 @@ fn verb_kind_confront_roundtrip() {
     let decoded: ObserverSnapshot = rmp_serde::from_slice(&bytes).expect("deserialize");
 
     assert_eq!(decoded.nearby_interactions.len(), 1);
-    assert_eq!(decoded.nearby_interactions[0].verbs[0].kind, VerbKind::Confront);
+    assert_eq!(
+        decoded.nearby_interactions[0].verbs[0].kind,
+        VerbKind::Confront
+    );
     assert_eq!(decoded.nearby_interactions[0].verbs[0].label, "Confront");
 }
 
@@ -541,15 +588,16 @@ fn verb_kind_confront_roundtrip() {
 /// Used in Phase 2 label relabeling — must survive the wire.
 #[test]
 fn all_character_archetype_variants_roundtrip() {
-    let archetypes = [
-        CharacterArchetype::Smuggler,
-        CharacterArchetype::Detective,
-    ];
+    let archetypes = [CharacterArchetype::Smuggler, CharacterArchetype::Detective];
 
     for archetype in archetypes {
         let bytes = rmp_serde::to_vec_named(&archetype).expect("serialize");
         let decoded: CharacterArchetype = rmp_serde::from_slice(&bytes).expect("deserialize");
-        assert_eq!(decoded, archetype, "CharacterArchetype::{:?} roundtrip failed", archetype);
+        assert_eq!(
+            decoded, archetype,
+            "CharacterArchetype::{:?} roundtrip failed",
+            archetype
+        );
     }
 }
 
@@ -575,7 +623,10 @@ fn nearby_interaction_contradicted_roundtrip() {
     let bytes = rmp_serde::to_vec_named(&snapshot).expect("serialize");
     let decoded: ObserverSnapshot = rmp_serde::from_slice(&bytes).expect("deserialize");
 
-    assert!(decoded.nearby_interactions[0].contradicted, "contradicted flag should survive roundtrip");
+    assert!(
+        decoded.nearby_interactions[0].contradicted,
+        "contradicted flag should survive roundtrip"
+    );
 }
 
 /// NearbyInteraction.object_type round-trips through MessagePack (#422).
@@ -600,5 +651,8 @@ fn nearby_interaction_object_type_roundtrip() {
     let bytes = rmp_serde::to_vec_named(&snapshot).expect("serialize");
     let decoded: ObserverSnapshot = rmp_serde::from_slice(&bytes).expect("deserialize");
 
-    assert_eq!(decoded.nearby_interactions[0].object_type, Some(ObjectType::Container));
+    assert_eq!(
+        decoded.nearby_interactions[0].object_type,
+        Some(ObjectType::Container)
+    );
 }