feat(simulation): add proximity detection and interaction verbs

Implement compute_nearby_interactions system that detects entities
within close (≤2) and mid (≤5) Manhattan distance, computes
available verbs per D-060 spec. NPCs get Talk+Observe at close
range, Observe-only at mid range; PersonOfInterest flips priority.
Objects get Examine. Results populate nearby_interactions[] on
ObserverSnapshot v4. Bump protocol version 3→4. Implements #404.

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

server/src/perception/interpretation.rs

@@ -199,6 +199,7 @@ mod tests {
         world.init_resource::<crate::knowledge::KnowledgeEventQueue>();
         world.init_resource::<EntityRegistry>();
         world.init_resource::<ObservationEventQueue>();
+        world.init_resource::<crate::simulation::interaction::NearbyInteractionBuffer>();
         world
     }
 

server/src/perception/observation.rs

@@ -99,6 +99,7 @@ mod tests {
         world.init_resource::<SnapshotBuffer>();
         world.init_resource::<KnowledgeEventQueue>();
         world.init_resource::<EntityRegistry>();
+        world.init_resource::<crate::simulation::interaction::NearbyInteractionBuffer>();
         world
     }
 

server/src/perception/observer.rs

@@ -11,6 +11,7 @@ use crate::bridge::types::*;
 use crate::knowledge::{EntityRegistry, KnowledgeGraph};
 use crate::perception::shadowcast::compute_fov;
 use crate::perception::vision_cone::{apply_vision_cone, Facing, VisionConeConfig};
+use crate::simulation::interaction::NearbyInteractionBuffer;
 use crate::simulation::movement::{PlayerCharacter, TilePosition, WalkabilityMap};
 use crate::simulation::time::SimulationTime;
 
@@ -22,6 +23,7 @@ pub fn compute_observer_snapshot(
     time: Res<SimulationTime>,
     walkability: Res<WalkabilityMap>,
     registry: Res<EntityRegistry>,
+    interaction_buffer: Res<NearbyInteractionBuffer>,
     observer_query: Query<(&TilePosition, Option<&Facing>, &KnowledgeGraph), With<PlayerCharacter>>,
     all_entities: Query<(
         Entity,
@@ -185,7 +187,8 @@ pub fn compute_observer_snapshot(
         day: time.day(),
         time_of_day: time.time_of_day_minutes(),
         day_phase: time.day_phase(),
-        paused: time.paused,
+        paused: time.paused(),
+        tick_rate: time.tick_rate,
     };
 
     tracing::trace!(
@@ -196,14 +199,15 @@ pub fn compute_observer_snapshot(
         visible_tiles.len(),
     );
 
-    // Step 8: Assemble snapshot (v3: added relationship + observation fields)
+    // Step 8: Assemble snapshot (v4: added nearby_interactions)
     buffer.snapshot = Some(ObserverSnapshot {
-        version: 3,
+        version: 4,
         tick: time.tick,
         game_time,
         player_facing: facing,
         entities,
         visible_tiles,
+        nearby_interactions: interaction_buffer.interactions.clone(),
     });
 }
 
@@ -221,6 +225,7 @@ mod tests {
         world.insert_resource(WalkabilityMap::new(width, height, 1));
         world.init_resource::<SnapshotBuffer>();
         world.init_resource::<EntityRegistry>();
+        world.init_resource::<NearbyInteractionBuffer>();
         world
     }
 
@@ -240,7 +245,7 @@ mod tests {
 
         let buffer = world.resource::<SnapshotBuffer>();
         let snapshot = buffer.snapshot.as_ref().expect("snapshot should exist");
-        assert_eq!(snapshot.version, 3);
+        assert_eq!(snapshot.version, 4);
         assert_eq!(snapshot.entities.len(), 1);
         assert!(matches!(snapshot.entities[0].kind, EntityKind::Player));
         assert_eq!(snapshot.entities[0].observation, EntityVisibility::Visible);
@@ -359,10 +364,10 @@ mod tests {
     #[test]
     fn game_time_populated() {
         let mut world = setup_world(32, 32);
-        world.insert_resource(SimulationTime {
-            tick: 7200, // 720 minutes = Evening
-            paused: true,
-        });
+        let mut time = SimulationTime::default();
+        time.tick = 7200; // 720 minutes = Evening
+        time.tick_rate = crate::simulation::time::TickRate::Paused;
+        world.insert_resource(time);
         world.spawn((
             PlayerCharacter,
             TilePosition::new(16, 16, 0),
@@ -479,7 +484,7 @@ mod tests {
             .id();
         registry.register(player);
         world.insert_resource(registry);
-        world.insert_resource(SimulationTime { tick: 100, paused: false });
+        world.insert_resource({ let mut t = SimulationTime::default(); t.tick = 100; t });
 
         let mut schedule = bevy_ecs::schedule::Schedule::default();
         schedule.add_systems(compute_observer_snapshot);