fix duplicate heads collecting

turns out we did not consider the ActiveHeads just duplicates in the backpack

crates/shared/src/backpack/mod.rs

@@ -4,7 +4,10 @@ use crate::{
     protocol::PlaySound,
 };
 use crate::{
-    cash::CashCollectEvent, global_observer, head_drop::HeadCollected, heads::HeadState,
+    cash::CashCollectEvent,
+    global_observer,
+    head_drop::HeadCollected,
+    heads::{ActiveHeads, HeadState},
     heads_database::HeadsDatabase,
 };
 use bevy::prelude::*;
@@ -155,14 +158,14 @@ fn sync_backpack_ui(backpack: &Backpack, state: &mut BackpackUiState, time: f32)
 fn on_head_collect(
     trigger: On<HeadCollected>,
     mut cmds: Commands,
-    mut backpack: Query<&mut Backpack>,
+    mut query: Query<(&mut Backpack, &ActiveHeads)>,
     heads_db: Res<HeadsDatabase>,
 ) -> Result {
     let HeadCollected { head, entity } = *trigger.event();
 
-    let mut backpack = backpack.get_mut(entity)?;
+    let (mut backpack, active_heads) = query.get_mut(entity)?;
 
-    if backpack.contains(head) {
+    if backpack.contains(head) || active_heads.contains(head) {
         cmds.trigger(CashCollectEvent);
     } else {
         backpack.insert(head, heads_db.as_ref());

crates/shared/src/heads/mod.rs

@@ -171,6 +171,10 @@ impl ActiveHeads {
 
         None
     }
+
+    pub fn contains(&self, head: usize) -> bool {
+        self.heads.iter().any(|h| h.is_some_and(|h| h.head == head))
+    }
 }
 
 #[derive(Event)]