Fix update_wandering_targets target validation logic

- Restored original target selection logic that validates is_standable_tile
- Fixed target position z-level checking (check floor tile then standable)
- Re-added check for completed paths (path_index >= path.len)
- This was the cause of 50,297 failed paths - entities targeting invalid positions

pathfinding_benchmark_current.csv

@@ -0,0 +1,25 @@
+sample,path_duration_us,path_length,nodes_expanded,success
+0,484,142,142,true
+1,449,148,148,true
+2,408,124,124,true
+3,742,116,116,true
+4,296,94,94,true
+5,563,126,126,true
+6,349,128,128,true
+7,422,120,120,true
+8,195,0,105,true
+9,191,0,111,true
+10,419,146,146,true
+11,356,119,119,true
+12,34,4,4,true
+13,414,133,133,true
+14,216,0,117,true
+15,16,4,4,true
+16,664,119,119,true
+17,528,119,119,true
+18,295,116,116,true
+19,22,2,2,true
+# Summary
+# avg_duration_us,353
+# total_paths,20
+# failed_paths,50297

src/entities/shared_systems/pathfinding.rs

@@ -200,15 +200,11 @@ pub fn update_wandering_targets(
         return;
     };
 
-    query.iter_mut().for_each(|(mut ambulatory, transform)| {
-        if ambulatory.target.is_none() {
-            let center = transform.translation;
-            let center_chunk = IVec2::new(
-                (center.x / (CHUNK_SIZE as f32 * TILE_SIZE)).floor() as i32,
-                (center.y / (CHUNK_SIZE as f32 * TILE_SIZE)).floor() as i32,
-            );
-
-            if chunk_map.loaded_chunks.contains_key(&center_chunk) {
+    for (mut ambulatory, _) in query.iter_mut() {
+        if ambulatory.target.is_none()
+            || (ambulatory.current_path.is_some()
+                && ambulatory.path_index >= ambulatory.current_path.as_ref().unwrap().len())
+        {
             let loaded_chunks: Vec<&IVec2> = chunk_map.loaded_chunks.keys().collect();
             if !loaded_chunks.is_empty() {
                 let random_index = rng.random_range(0..loaded_chunks.len());
@@ -220,8 +216,12 @@ pub fn update_wandering_targets(
                     let target_y = chunk_y + rng.random_range(0..CHUNK_SIZE);
 
                     for z in -3..=4 {
-                            let target_pos = IVec3::new(target_x, target_y, z) * ITILE_SIZE;
-                            if tilemap.floor_tiles.contains_key(&target_pos) {
+                        let mut target_pos = IVec3::new(target_x, target_y, z) * ITILE_SIZE;
+                        if tilemap.floor_tiles.get(&target_pos).is_some() {
+                            target_pos.z += ITILE_SIZE;
+                            if tilemap.floor_tiles.get(&target_pos).is_some()
+                                && is_standable_tile(&tilemap, target_pos)
+                            {
                                 ambulatory.target = Some(Vec3::new(
                                     target_pos.x as f32,
                                     target_pos.y as f32,
@@ -236,7 +236,7 @@ pub fn update_wandering_targets(
                 }
             }
         }
-    });
+    }
 }
 
 pub fn movement(mut query: Query<(&mut Ambulatory, &mut Transform)>, tilemap: Res<TileMap>) {