M1d: creatures, hunting, weapons, food buffs and the hide cloak

- Rabbits, deer and boars with procedural meshes and animated legs, a
  state machine (idle/wander/flee/charge/dead) and heightmap steering that
  avoids water, cliffs, the world edge, trees and buildings
- Spawner keeps a habitat-based budget around the player (6/4/3)
- Melee needs a weapon or tool (club, spear, axe, pickaxe); box sweep hits
- Wooden spear (thrust or throw) and crude bow with draw-scaled arrows;
  projectiles stick in the world as saved pickups
- Carcasses: E to butcher for meat, hide and embedded arrows
- Boars charge and gore when hit; hurt flash and a brief healing pause
- Cooked meat gives Well fed (faster stamina and healing); buffs saved
- Hide cloak: wear for warmth, saved, goes in the grave on death
- Feathers as meadow pickups (appended, existing save ids unchanged)
- New test_creatures_combat suite; run_all.sh gets a per-suite time limit

scripts/creatures/projectile.gd

@@ -0,0 +1,87 @@
+extends Node3D
+## A flying arrow or thrown spear.
+##
+## Each physics step it moves along its velocity (with gravity) and ray-casts
+## the segment it covered, so fast arrows can't skip through a thin target.
+## - Hits an animal: damage scaled by speed. An arrow sticks in the animal and
+##   comes back when you butcher it. A spear drops at the animal's feet.
+## - Hits anything else: it sticks there and becomes a pickup.
+## - After 8 s in the air (or below the world) it drops where it is.
+
+var item_id := "arrow"
+var damage := 10.0
+var velocity := Vector3.ZERO
+var gravity := 9.8
+var shooter: Node3D
+var world: Node3D
+var _life := 8.0
+var _start_speed := 1.0
+
+func setup(id: String, w: Node3D, from: Vector3, vel: Vector3, dmg: float, who: Node3D) -> void:
+	item_id = id
+	world = w
+	velocity = vel
+	damage = dmg
+	shooter = who
+	_start_speed = maxf(vel.length(), 0.1)
+	gravity = 9.8 if id == "arrow" else 12.0
+	var mi := MeshInstance3D.new()
+	mi.mesh = ItemDB.mesh_for(id)
+	mi.material_override = ItemDB.item_material()
+	if id == "spear":
+		# The spear mesh runs along +Y; turn it to fly point-first along -Z.
+		mi.transform = Transform3D(Basis(Vector3.RIGHT, -PI * 0.5), Vector3(0, 0, 0.35))
+	add_child(mi)
+	position = from
+	_orient()
+
+func _orient() -> void:
+	if velocity.length() > 0.01 and is_inside_tree():
+		look_at(global_position + velocity, Vector3.UP if absf(velocity.normalized().y) < 0.99 else Vector3.RIGHT)
+
+func _ready() -> void:
+	_orient()
+
+func _physics_process(delta: float) -> void:
+	step(delta)
+
+func step(dt: float) -> void:
+	_life -= dt
+	var from := global_position
+	velocity.y -= gravity * dt
+	var to := from + velocity * dt
+	var ex: Array[RID] = []
+	if shooter != null:
+		ex.append(shooter.get_rid())
+	var q := PhysicsRayQueryParameters3D.create(from, to, 1 | 8, ex)
+	var hit := get_world_3d().direct_space_state.intersect_ray(q)
+	if not hit.is_empty():
+		_on_hit(hit)
+		return
+	global_position = to
+	_orient()
+	if _life <= 0.0 or to.y < world.terrain.min_height - 20.0:
+		_drop(Transform3D(Basis(), Vector3(to.x, world.terrain.sample_height(to.x, to.z), to.z)))
+
+func _on_hit(hit: Dictionary) -> void:
+	var c: Object = hit.collider
+	var dir := velocity.normalized()
+	if c != null and (c as Node).is_in_group("creature"):
+		var k := clampf(velocity.length() / _start_speed, 0.4, 1.0)
+		Actions.projectile_hit(shooter, c, damage * k, global_position, item_id if item_id == "arrow" else "")
+		if item_id == "spear":
+			var at: Vector3 = (c as Node3D).global_position + Vector3(0, 0.05, 0)
+			_drop(Transform3D(Basis(Vector3.UP, randf() * TAU) * Basis(Vector3.FORWARD, PI * 0.5), at))
+		else:
+			queue_free()
+		return
+	# Stick into whatever it hit, point first, slightly buried.
+	var at: Vector3 = hit.position - dir * (0.12 if item_id == "arrow" else 0.25)
+	var b := Basis.looking_at(dir, Vector3.UP if absf(dir.y) < 0.99 else Vector3.RIGHT)
+	if item_id == "spear":
+		b = b * Basis(Vector3.RIGHT, -PI * 0.5)   # mesh +Y along the flight
+	_drop(Transform3D(b, at))
+
+func _drop(xf: Transform3D) -> void:
+	world.drop_item(item_id, 1, xf)
+	queue_free()