fix: remove collision_delay to eliminate movement deadlock

collision_delay was causing entities to skip step_recovery ticks, freezing
movement whenever the next tile was occupied. Combined with the ordering fix
(collision_delay placed before step_recovery), entities were stuck at
path_index=0 indefinitely in spawn clusters.

Remove collision_delay entirely — step_recovery already provides the
per-tick pacing, and the natural next-tick retry (via left-step or
normal movement) handles occupied tiles without an artificial delay.

Actual thresholds (grass weight=50): dorfs move after 6 ticks, pigs after
26 ticks, rabbits after 2 ticks. Without collision_delay interference,
movement is now governed purely by step_recovery.

src/entities/livestock/pig.rs

@@ -30,7 +30,6 @@ impl Pig {
                 path_index: 0,
                 step_recovery: 0,
                 validation_cooldown: 0,
-                collision_delay: 0,
             },
             sprite: Sprite {
                 image: asset_server.load("pig.png"),

src/entities/livestock/rabbit.rs

@@ -27,7 +27,6 @@ impl Rabbit {
                 path_index: 0,
                 step_recovery: 0,
                 validation_cooldown: 0,
-                collision_delay: 0,
             },
             sprite: Sprite {
                 image: asset_server.load("rabbit.png"),

src/entities/sentient/dorf.rs

@@ -27,7 +27,6 @@ impl Dorf {
                 path_index: 0,
                 step_recovery: 0,
                 validation_cooldown: 0,
-                collision_delay: 0,
             },
             sprite: Sprite {
                 image: asset_server.load("dorf.png"),

src/entities/shared_components/ambulatory.rs

@@ -10,7 +10,6 @@ pub struct Ambulatory {
     pub target: Option<Vec3>,
     pub step_recovery: u32,
     pub validation_cooldown: u8,
-    pub collision_delay: u8,
 }
 
 impl Default for Ambulatory {
@@ -23,7 +22,6 @@ impl Default for Ambulatory {
             target: None,
             step_recovery: 0,
             validation_cooldown: 0,
-            collision_delay: 0,
         }
     }
 }

src/entities/shared_systems/pathfinding.rs

@@ -592,11 +592,6 @@ pub fn movement(
                 }
             }
 
-            if ambulatory.collision_delay > 0 {
-                ambulatory.collision_delay -= 1;
-                return;
-            }
-
             if let Some(path) = &ambulatory.current_path {
                 if ambulatory.path_index < path.len() {
                     let next_point = path[ambulatory.path_index];
@@ -624,13 +619,9 @@ pub fn movement(
                                     transform.scale.x = -PIXEL_RATIO;
                                 }
                                 transform.translation = left_point;
-                                return;
                             }
                         }
-                        ambulatory.collision_delay = 1;
+                    } else {
-                        return;
-                    }
-
                         let direction = (next_point - transform.translation).normalize();
                         transform.translation = next_point;
 
@@ -643,6 +634,7 @@ pub fn movement(
                         if transform.translation.distance(next_point) < TILE_SIZE {
                             ambulatory.path_index += 1;
                         }
+                    }
                 } else {
                     ambulatory.current_path = None;
                     if let Some(target) = ambulatory.target {