simple hitpoint mechanic

src/main.rs

@@ -6,8 +6,10 @@ mod cash;
 mod gates;
 mod heads_ui;
 mod movables;
+mod npc;
 mod platforms;
 mod player;
+mod shooting;
 mod tb_entities;
 
 use avian3d::PhysicsPlugins;
@@ -76,6 +78,8 @@ fn main() {
     app.add_plugins(movables::plugin);
     app.add_plugins(billboards::plugin);
     app.add_plugins(aim::plugin);
+    app.add_plugins(shooting::plugin);
+    app.add_plugins(npc::plugin);
 
     app.insert_resource(AmbientLight {
         color: Color::WHITE,