WIP: feat(scene) integrate beauty pass — shader water, building blockouts, wind, smoke, 6 textures

- Add 3 missing Terrain3D textures: Dirt Path (id=3), Riverbank Stone (id=4),
  Compacted Ground (id=5) with procedural albedo PNGs + generate tool
- Replace greybox river BoxMesh with animated vertex-displacement water shader
- Replace greybox waterfall BoxMesh with scrolling-UV waterfall shader
- Add WaterfallMist GPUParticles3D with upward drift and alpha fade
- Add wind vertex shader for tree canopies (sin-based, height-weighted sway)
- Replace StylizedTree.tscn with script-driven procedural tree supporting
  3 canopy color variants and position-based randomization
- Replace greybox house boxes with StylizedHouse (walls + pitched roof + door)
- Replace mill box with StylizedMill (body + roof + water wheel cylinder)
- Replace fortress box with FortressBlockout (keep + parapet + corner turret)
- Replace bridge box with BridgeBlockout (deck + pillar supports)
- Add ChimneySmoke GPUParticles3D on each house roof
- Height-snap buildings (fortress + village) to terrain surface in _ready()
- Update JajceWorld.tscn: remove all greybox landmark sub-resources, instance
  new scenes, keep terrain/navigation/sky/fog as-is
- Update scaffold test for new scene structure and beauty elements

world/jajce/StylizedTree.gd

@@ -0,0 +1,58 @@
+extends Node3D
+
+enum CanopyVariant {
+	GREEN,
+	DARK_GREEN,
+	YELLOW_GREEN,
+}
+
+@export var canopy_variant: CanopyVariant = CanopyVariant.GREEN
+@export var canopy_radius: float = 1.35
+
+const COLORS := {
+	CanopyVariant.GREEN: Color(0.19, 0.38, 0.17),
+	CanopyVariant.DARK_GREEN: Color(0.12, 0.30, 0.12),
+	CanopyVariant.YELLOW_GREEN: Color(0.30, 0.42, 0.15),
+}
+
+const WIND_SHADER := preload("res://world/jajce/materials/wind.gdshader")
+
+func _ready() -> void:
+	for child in get_children():
+		child.queue_free()
+
+	var hash_seed := hash(global_position)
+	var rng := RandomNumberGenerator.new()
+	rng.seed = hash_seed
+	canopy_variant = rng.randi() % COLORS.size() as CanopyVariant
+	canopy_radius = 1.0 + rng.randf() * 0.8
+
+	var trunk_mesh := CylinderMesh.new()
+	trunk_mesh.top_radius = 0.22
+	trunk_mesh.bottom_radius = 0.32
+	trunk_mesh.height = 2.8
+
+	var trunk_mat := StandardMaterial3D.new()
+	trunk_mat.albedo_color = Color(0.27, 0.16, 0.09)
+	trunk_mat.roughness = 0.95
+	trunk_mesh.material = trunk_mat
+
+	var trunk := MeshInstance3D.new()
+	trunk.mesh = trunk_mesh
+	trunk.position = Vector3(0, 1.4, 0)
+	add_child(trunk)
+
+	var canopy_mesh := SphereMesh.new()
+	canopy_mesh.radius = canopy_radius
+	canopy_mesh.height = 2.4
+
+	var canopy_mat := ShaderMaterial.new()
+	canopy_mat.shader = WIND_SHADER
+	canopy_mat.set_shader_parameter("albedo", COLORS[canopy_variant])
+	canopy_mat.set_shader_parameter("roughness", 0.9)
+	canopy_mesh.material = canopy_mat
+
+	var canopy := MeshInstance3D.new()
+	canopy.mesh = canopy_mesh
+	canopy.position = Vector3(0, 3.2 + (canopy_radius - 1.35) * 0.5, 0)
+	add_child(canopy)