feat(simulation): add proof room with wall and NPC (#357)

Wall at (16,14) and NPC at (16,13) for Sprint 2 fog-of-perception
proof. Player starts at (16,16) — NPC hidden behind wall until
player moves around it.

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

server/src/main.rs

@@ -7,6 +7,7 @@ use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 use settled_reach_server::bridge::tcp::TcpBridge;
 use settled_reach_server::bridge::{BridgePlugin, BridgeResource, ServerRunning};
 use settled_reach_server::knowledge::{KnowledgeGraph, KnowledgePlugin};
+use settled_reach_server::npc::Npc;
 use settled_reach_server::perception::vision_cone::Facing;
 use settled_reach_server::simulation::movement::{PlayerCharacter, TilePosition, WalkabilityMap};
 use settled_reach_server::simulation::SimulationPlugin;
@@ -42,12 +43,22 @@ fn main() {
     app.add_plugins(KnowledgePlugin);
     app.insert_resource(BridgeResource::new(bridge));
     app.insert_resource(WalkabilityMap::new(32, 32, 1));
+
+    // Proof room: wall at (16,14) between player and NPC
+    // NPC at (16,13) hidden behind wall until player moves around it
+    {
+        let mut wm = app.world_mut().resource_mut::<WalkabilityMap>();
+        wm.set_walkable(&TilePosition::new(16, 14, 0), false);
+    }
+
     app.world_mut().spawn((
         PlayerCharacter,
         TilePosition::new(16, 16, 0),
         Facing::default(),
         KnowledgeGraph::new(),
     ));
+    app.world_mut()
+        .spawn((Npc, TilePosition::new(16, 13, 0)));
 
     tracing::info!("Simulation initialized, entering game loop");