NS-23: bump step-off bypass using floor-under-feet, not body Y

Ray down for floor Y under the capsule; skip nav only when goal is a bit
lower than that surface, drop ≤0.55 m, and horiz ≤1.05 m. Matches
leaving a bump without comparing pick/body origin (which broke obstacle
pathing). Long crosses still use waypoints.

client/scripts/player.gd

@@ -6,12 +6,16 @@ extends CharacterBody3D
 ## and steps comes from `move_and_slide` + floor_* on CharacterBody3D. Move **legality** (step,
 ## distance, bounds) is server MoveCommand only — not reimplemented here.
 ##
-## Nav for detours; if next waypoint has almost no xz offset, steer xz toward goal.
+## Nav for detours; short local step-down (feet vs goal Y, not body origin) may bypass waypoints.
 
 const MOVE_SPEED: float = 5.0
 const ARRIVE_EPS: float = 0.35
 const VERT_ARRIVE_EPS: float = 0.055
 const DIRECT_APPROACH_RADIUS: float = 0.85
+const FLOOR_PROBE_DOWN: float = 4.0
+const STEP_OFF_FLOOR_MARGIN: float = 0.04
+const STEP_OFF_MAX_DROP: float = 0.55
+const STEP_OFF_MAX_HORIZ: float = 1.05
 
 var _has_walk_goal: bool = false
 var _auth_walk_goal: Vector3 = Vector3.ZERO
@@ -42,6 +46,37 @@ func snap_to_server(world_pos: Vector3) -> void:
 	_nav_agent.set_target_position(world_pos)
 
 
+func _floor_y_under_body() -> float:
+	var space: PhysicsDirectSpaceState3D = get_world_3d().direct_space_state
+	var from: Vector3 = global_position
+	var to: Vector3 = from + Vector3(0.0, -FLOOR_PROBE_DOWN, 0.0)
+	var q: PhysicsRayQueryParameters3D = PhysicsRayQueryParameters3D.create(from, to)
+	q.collision_mask = 1
+	q.exclude = [get_rid()]
+	var hit: Dictionary = space.intersect_ray(q)
+	if hit.is_empty():
+		return global_position.y
+	var pv: Variant = hit.get("position")
+	if pv is Vector3:
+		return (pv as Vector3).y
+	return global_position.y
+
+
+func _nav_short_step_down_use_goal_direct() -> bool:
+	var floor_y: float = _floor_y_under_body()
+	if _auth_walk_goal.y >= floor_y - STEP_OFF_FLOOR_MARGIN:
+		return false
+	var drop: float = floor_y - _auth_walk_goal.y
+	if drop > STEP_OFF_MAX_DROP:
+		return false
+	var hd: float = Vector2(
+		_auth_walk_goal.x - global_position.x, _auth_walk_goal.z - global_position.z
+	).length()
+	if hd > STEP_OFF_MAX_HORIZ:
+		return false
+	return true
+
+
 func _set_horizontal_velocity_toward(point: Vector3) -> void:
 	var pos := global_position
 	var dh: Vector3 = Vector3(point.x - pos.x, 0.0, point.z - pos.z)
@@ -73,6 +108,11 @@ func _physics_process(_delta: float) -> void:
 		move_and_slide()
 		return
 
+	if _nav_short_step_down_use_goal_direct():
+		_set_horizontal_velocity_toward(_auth_walk_goal)
+		move_and_slide()
+		return
+
 	if horiz_dist <= DIRECT_APPROACH_RADIUS:
 		_set_horizontal_velocity_toward(_auth_walk_goal)
 	else: